diff --git a/components/bt/host/bluedroid/api/esp_gatt_common_api.c b/components/bt/host/bluedroid/api/esp_gatt_common_api.c
index 7a26013b8..983092516 100644
--- a/components/bt/host/bluedroid/api/esp_gatt_common_api.c
+++ b/components/bt/host/bluedroid/api/esp_gatt_common_api.c
@@ -49,10 +49,35 @@ esp_err_t esp_ble_gatt_set_local_mtu (uint16_t mtu)
 }
 
 #if (BLE_INCLUDED == TRUE)
-extern uint16_t L2CA_GetFreePktBufferNum_LE(void);
+extern UINT16 L2CA_GetFreePktBufferNum_LE(void);
 
-uint16_t esp_ble_get_sendable_packets_num ()
+/**
+ * @brief           This function is called to get currently sendable packets number on controller,
+ *                  the function is called only in BLE running core and single connection now.
+ *
+ * @return
+ *                  sendable packets number on controller
+ *
+ */
+ 
+uint16_t esp_ble_get_sendable_packets_num (void)
 {
     return L2CA_GetFreePktBufferNum_LE();
 }
+
+/**
+ * @brief           This function is used to query the number of available buffers for the current connection.
+ *                  When you need to query the current available buffer number, it is recommended to use this API.
+ * @param[in]       conn_id: current connection id.
+ * 
+ * @return
+ *                  Number of available buffers for the current connection
+ *
+ */
+ 
+extern UINT16 L2CA_GetCurFreePktBufferNum_LE(UINT16 conn_id);
+uint16_t esp_ble_get_cur_sendable_packets_num (uint16_t connid)
+{
+    return L2CA_GetCurFreePktBufferNum_LE(connid);
+}
 #endif
\ No newline at end of file
diff --git a/components/bt/host/bluedroid/api/esp_gattc_api.c b/components/bt/host/bluedroid/api/esp_gattc_api.c
index c8da7bcec..a3a086a85 100644
--- a/components/bt/host/bluedroid/api/esp_gattc_api.c
+++ b/components/bt/host/bluedroid/api/esp_gattc_api.c
@@ -431,7 +431,9 @@ esp_err_t esp_ble_gattc_write_char(esp_gatt_if_t gattc_if,
     arg.write_char.value = value;
     arg.write_char.write_type = write_type;
     arg.write_char.auth_req = auth_req;
-
+    if(write_type == ESP_GATT_WRITE_TYPE_NO_RSP){
+        l2ble_update_att_acl_pkt_num(L2CA_ADD_BTC_NUM, NULL);
+    }
     return (btc_transfer_context(&msg, &arg, sizeof(btc_ble_gattc_args_t), btc_gattc_arg_deep_copy) == BT_STATUS_SUCCESS ? ESP_OK : ESP_FAIL);
 }
 
@@ -461,7 +463,9 @@ esp_err_t esp_ble_gattc_write_char_descr (esp_gatt_if_t gattc_if,
     arg.write_descr.value = value;
     arg.write_descr.write_type = write_type;
     arg.write_descr.auth_req = auth_req;
-
+    if(write_type == ESP_GATT_WRITE_TYPE_NO_RSP){
+        l2ble_update_att_acl_pkt_num(L2CA_ADD_BTC_NUM, NULL);
+    }
     return (btc_transfer_context(&msg, &arg, sizeof(btc_ble_gattc_args_t), btc_gattc_arg_deep_copy) == BT_STATUS_SUCCESS ? ESP_OK : ESP_FAIL);
 }
 
diff --git a/components/bt/host/bluedroid/api/esp_gatts_api.c b/components/bt/host/bluedroid/api/esp_gatts_api.c
index 80d89b30b..91edc26b5 100644
--- a/components/bt/host/bluedroid/api/esp_gatts_api.c
+++ b/components/bt/host/bluedroid/api/esp_gatts_api.c
@@ -273,7 +273,9 @@ esp_err_t esp_ble_gatts_send_indicate(esp_gatt_if_t gatts_if, uint16_t conn_id,
     arg.send_ind.need_confirm = need_confirm;
     arg.send_ind.value_len = value_len;
     arg.send_ind.value = value;
-
+    if(need_confirm == false){
+        l2ble_update_att_acl_pkt_num(L2CA_ADD_BTC_NUM, NULL);
+    }
     return (btc_transfer_context(&msg, &arg, sizeof(btc_ble_gatts_args_t),
                                  btc_gatts_arg_deep_copy) == BT_STATUS_SUCCESS ? ESP_OK : ESP_FAIL);
 }
diff --git a/components/bt/host/bluedroid/api/include/api/esp_gatt_common_api.h b/components/bt/host/bluedroid/api/include/api/esp_gatt_common_api.h
index bee2c28f0..447a26bd9 100644
--- a/components/bt/host/bluedroid/api/include/api/esp_gatt_common_api.h
+++ b/components/bt/host/bluedroid/api/include/api/esp_gatt_common_api.h
@@ -46,6 +46,7 @@ extern esp_err_t esp_ble_gatt_set_local_mtu (uint16_t mtu);
 
 #if (BLE_INCLUDED == TRUE)
 extern uint16_t esp_ble_get_sendable_packets_num (void);
+extern uint16_t esp_ble_get_cur_sendable_packets_num (uint16_t connid);
 #endif
 
 #ifdef __cplusplus
diff --git a/components/bt/host/bluedroid/bta/gatt/bta_gattc_api.c b/components/bt/host/bluedroid/bta/gatt/bta_gattc_api.c
index 6e4da29a2..55c17621c 100644
--- a/components/bt/host/bluedroid/bta/gatt/bta_gattc_api.c
+++ b/components/bt/host/bluedroid/bta/gatt/bta_gattc_api.c
@@ -31,7 +31,7 @@
 #include "bta/bta_sys.h"
 #include "bta/bta_gatt_api.h"
 #include "bta_gattc_int.h"
-
+#include "stack/l2c_api.h"
 /*****************************************************************************
 **  Constants
 *****************************************************************************/
@@ -602,7 +602,10 @@ void BTA_GATTC_WriteCharValue ( UINT16 conn_id,
             p_buf->p_value = (UINT8 *)(p_buf + 1);
             memcpy(p_buf->p_value, p_value, len);
         }
-
+        if(write_type == BTA_GATTC_TYPE_WRITE_NO_RSP){
+            l2ble_update_att_acl_pkt_num(L2CA_DECREASE_BTC_NUM, NULL);
+            l2ble_update_att_acl_pkt_num(L2CA_ADD_BTU_NUM, NULL);
+        }
         bta_sys_sendmsg(p_buf);
     }
     return;
@@ -649,7 +652,10 @@ void BTA_GATTC_WriteCharDescr (UINT16 conn_id,
             /* pack the descr data */
             memcpy(p_buf->p_value, p_data->p_value, p_data->len);
         }
-
+        if(write_type == BTA_GATTC_TYPE_WRITE_NO_RSP){
+            l2ble_update_att_acl_pkt_num(L2CA_DECREASE_BTC_NUM, NULL);
+            l2ble_update_att_acl_pkt_num(L2CA_ADD_BTU_NUM, NULL);
+        }
         bta_sys_sendmsg(p_buf);
     }
     return;
diff --git a/components/bt/host/bluedroid/bta/gatt/bta_gatts_act.c b/components/bt/host/bluedroid/bta/gatt/bta_gatts_act.c
index 87962b1d4..7658c7b1a 100644
--- a/components/bt/host/bluedroid/bta/gatt/bta_gatts_act.c
+++ b/components/bt/host/bluedroid/bta/gatt/bta_gatts_act.c
@@ -674,6 +674,7 @@ void bta_gatts_indicate_handle (tBTA_GATTS_CB *p_cb, tBTA_GATTS_DATA *p_msg)
                                                       p_msg->api_indicate.len,
                                                       p_msg->api_indicate.value);
             } else {
+                l2ble_update_att_acl_pkt_num(L2CA_DECREASE_BTU_NUM, NULL);
                 status = GATTS_HandleValueNotification (p_msg->api_indicate.hdr.layer_specific,
                                                         p_msg->api_indicate.attr_id,
                                                         p_msg->api_indicate.len,
diff --git a/components/bt/host/bluedroid/bta/gatt/bta_gatts_api.c b/components/bt/host/bluedroid/bta/gatt/bta_gatts_api.c
index 5397c6487..f06a2976e 100644
--- a/components/bt/host/bluedroid/bta/gatt/bta_gatts_api.c
+++ b/components/bt/host/bluedroid/bta/gatt/bta_gatts_api.c
@@ -31,6 +31,7 @@
 #include "bta/bta_gatt_api.h"
 #include "bta_gatts_int.h"
 #include "osi/allocator.h"
+#include "stack/l2c_api.h"
 
 /*****************************************************************************
 **  Constants
@@ -426,6 +427,10 @@ void BTA_GATTS_HandleValueIndication (UINT16 conn_id, UINT16 attr_id, UINT16 dat
             memcpy(p_buf->value, p_data, data_len);
 
         }
+        if(need_confirm == false){
+            l2ble_update_att_acl_pkt_num(L2CA_DECREASE_BTC_NUM, NULL);
+            l2ble_update_att_acl_pkt_num(L2CA_ADD_BTU_NUM, NULL);
+        }
         bta_sys_sendmsg(p_buf);
     }
     return;
diff --git a/components/bt/host/bluedroid/stack/gatt/gatt_cl.c b/components/bt/host/bluedroid/stack/gatt/gatt_cl.c
index 4ffd7ca5a..56a11dd8e 100644
--- a/components/bt/host/bluedroid/stack/gatt/gatt_cl.c
+++ b/components/bt/host/bluedroid/stack/gatt/gatt_cl.c
@@ -219,6 +219,7 @@ void gatt_act_write (tGATT_CLCB *p_clcb, UINT8 sec_act)
     if (p_attr) {
         switch (p_clcb->op_subtype) {
         case GATT_WRITE_NO_RSP:
+            l2ble_update_att_acl_pkt_num(L2CA_DECREASE_BTU_NUM, NULL);
             p_clcb->s_handle = p_attr->handle;
             op_code = (sec_act == GATT_SEC_SIGN_DATA) ? GATT_SIGN_CMD_WRITE : GATT_CMD_WRITE;
             rt = gatt_send_write_msg(p_tcb,
diff --git a/components/bt/host/bluedroid/stack/include/stack/l2c_api.h b/components/bt/host/bluedroid/stack/include/stack/l2c_api.h
index 33abaec7b..421b93d48 100644
--- a/components/bt/host/bluedroid/stack/include/stack/l2c_api.h
+++ b/components/bt/host/bluedroid/stack/include/stack/l2c_api.h
@@ -29,6 +29,7 @@
 #include "common/bt_target.h"
 #include "stack/l2cdefs.h"
 #include "stack/hcidefs.h"
+#include "osi/fixed_queue.h"
 
 /*****************************************************************************
 **  Constants
@@ -1228,7 +1229,21 @@ extern UINT16 L2CA_GetDisconnectReason (BD_ADDR remote_bda, tBT_TRANSPORT transp
 
 extern BOOLEAN L2CA_CheckIsCongest(UINT16 fixed_cid, UINT16 handle);
 
+#define  L2CA_GET_ATT_NUM      0
+#define  L2CA_ADD_BTC_NUM      1
+#define  L2CA_DECREASE_BTC_NUM 2
+#define  L2CA_ADD_BTU_NUM      3
+#define  L2CA_DECREASE_BTU_NUM 4
+#define  L2CA_BUFF_INI         5
+#define  L2CA_BUFF_DEINIT      6
 
+typedef struct {
+    UINT16 conn_id;
+    UINT16 * get_num;
+} tl2c_buff_param_t;
+
+
+extern void l2ble_update_att_acl_pkt_num(UINT8 type, tl2c_buff_param_t *param);
 
 #ifdef __cplusplus
 }
diff --git a/components/bt/host/bluedroid/stack/l2cap/include/l2c_int.h b/components/bt/host/bluedroid/stack/l2cap/include/l2c_int.h
index d24562e51..26075679b 100644
--- a/components/bt/host/bluedroid/stack/l2cap/include/l2c_int.h
+++ b/components/bt/host/bluedroid/stack/l2cap/include/l2c_int.h
@@ -74,6 +74,8 @@
 #define L2CAP_DEFAULT_MONITOR_TOUT   12000        /* 12000 milliseconds */
 #define L2CAP_FCR_ACK_TOUT           200          /* 200 milliseconds */
 
+#define L2CAP_CACHE_ATT_ACL_NUM      10
+
 /* Define the possible L2CAP channel states. The names of
 ** the states may seem a bit strange, but they are taken from
 ** the Bluetooth specification.
@@ -165,6 +167,9 @@ typedef enum {
 
 #define L2CAP_MAX_FCR_CFG_TRIES         2       /* Config attempts before disconnecting */
 
+#ifndef MIN
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#endif
 typedef uint8_t tL2C_BLE_FIXED_CHNLS_MASK;
 
 typedef struct {
diff --git a/components/bt/host/bluedroid/stack/l2cap/l2c_api.c b/components/bt/host/bluedroid/stack/l2cap/l2c_api.c
index 6bd1fadc8..859389c07 100644
--- a/components/bt/host/bluedroid/stack/l2cap/l2c_api.c
+++ b/components/bt/host/bluedroid/stack/l2cap/l2c_api.c
@@ -36,7 +36,7 @@
 #include "stack/btu.h"
 #include "stack/btm_api.h"
 #include "osi/allocator.h"
-
+#include "gatt_int.h"
 #if (CLASSIC_BT_INCLUDED == TRUE)
 /*******************************************************************************
 **
@@ -1877,6 +1877,15 @@ UINT16 L2CA_GetFreePktBufferNum_LE(void)
 {
     return l2cb.controller_le_xmit_window;
 }
+UINT16 L2CA_GetCurFreePktBufferNum_LE(UINT16 conn_id)
+{
+    uint16_t num = 0;
+    tl2c_buff_param_t param;
+    param.conn_id = conn_id;
+    param.get_num = &num;
+    l2ble_update_att_acl_pkt_num(L2CA_GET_ATT_NUM, &param);
+    return num;
+}
 #endif
 
 /*******************************************************************************
@@ -2265,3 +2274,89 @@ UINT16 L2CA_FlushChannel (UINT16 lcid, UINT16 num_to_flush)
     return (num_left);
 }
 
+
+/******************************************************************************
+**
+** Function         update_acl_pkt_num
+**
+** Description      Update the number of att acl packets to be sent in xmit_hold_q.
+**
+** Returns          None
+**
+*******************************************************************************/
+
+#if BLE_INCLUDED == TRUE
+void l2ble_update_att_acl_pkt_num(UINT8 type, tl2c_buff_param_t *param)
+{
+    static SemaphoreHandle_t buff_semaphore = NULL ;
+    static INT16 btc_buf;
+    static INT16 btu_buf;
+
+    if(buff_semaphore != NULL){
+        xSemaphoreTake(buff_semaphore, 10 / portTICK_PERIOD_MS);
+    }
+    switch (type)
+    {
+    case L2CA_ADD_BTC_NUM:{
+        btc_buf ++;
+        break;
+    }
+    case L2CA_DECREASE_BTC_NUM:{
+        btc_buf --;
+        break;
+    }
+    case L2CA_ADD_BTU_NUM:{
+        btu_buf ++;
+        break;
+    }
+    case L2CA_DECREASE_BTU_NUM:{
+        btu_buf --;
+        break;
+    }
+    case L2CA_GET_ATT_NUM:{
+        INT16 att_acl_pkt_num = 0;
+        INT16 att_max_num = 0;
+        *(param->get_num) = 0;
+        UINT8 tcb_idx = param->conn_id;
+        tGATT_TCB * p_tcb = gatt_get_tcb_by_idx(tcb_idx);
+        if (p_tcb == NULL){
+            L2CAP_TRACE_ERROR("%s not found p_tcb", __func__);
+            break;
+        }
+        tL2C_LCB * p_lcb = l2cu_find_lcb_by_bd_addr (p_tcb->peer_bda, BT_TRANSPORT_LE);
+        if (p_lcb == NULL){
+            L2CAP_TRACE_ERROR("%s not found p_lcb", __func__);
+            break;
+        }
+        fixed_queue_t * queue = p_lcb->p_fixed_ccbs[L2CAP_ATT_CID - L2CAP_FIRST_FIXED_CHNL]->xmit_hold_q;
+        att_max_num = MIN(p_lcb->link_xmit_quota, L2CAP_CACHE_ATT_ACL_NUM);
+        if (queue == NULL){
+            L2CAP_TRACE_ERROR("%s not found queue", __func__);
+            break;
+        }
+        att_acl_pkt_num = fixed_queue_length(queue);
+        if(att_acl_pkt_num < att_max_num){
+            if(btc_buf + btu_buf < att_max_num - att_acl_pkt_num){
+                *(param->get_num) = att_max_num - att_acl_pkt_num - (btc_buf + btu_buf);
+            }
+        }
+        break;
+    }
+    case L2CA_BUFF_INI:{
+        btc_buf = 0;
+        btu_buf = 0;
+        buff_semaphore = xSemaphoreCreateBinary();
+        xSemaphoreGive(buff_semaphore);
+        break;
+    }
+    case L2CA_BUFF_DEINIT:{
+        btc_buf = 0;
+        btu_buf = 0;
+        break;
+    }
+    default:
+        break;
+    }
+    xSemaphoreGive(buff_semaphore);
+}
+#endif
\ No newline at end of file
diff --git a/components/bt/host/bluedroid/stack/l2cap/l2c_link.c b/components/bt/host/bluedroid/stack/l2cap/l2c_link.c
index 22360ac84..960c455d8 100644
--- a/components/bt/host/bluedroid/stack/l2cap/l2c_link.c
+++ b/components/bt/host/bluedroid/stack/l2cap/l2c_link.c
@@ -1131,6 +1131,12 @@ void l2c_link_check_send_pkts (tL2C_LCB *p_lcb, tL2C_CCB *p_ccb, BT_HDR *p_buf)
             while ((l2cb.controller_xmit_window != 0) && (p_lcb->sent_not_acked < p_lcb->link_xmit_quota))
 #endif
             {
+                //need check flag: partial_segment_being_sent
+                if ( (p_lcb->partial_segment_being_sent)
+                        || (p_lcb->link_state != LST_CONNECTED)
+                        || (L2C_LINK_CHECK_POWER_MODE (p_lcb)) ) {
+                    break;
+                }
                 //L2CAP_TRACE_DEBUG("l2cu_get_next_buffer_to_send = %p",l2cu_get_next_buffer_to_send(p_lcb));
                 if ((p_buf = l2cu_get_next_buffer_to_send (p_lcb)) == NULL) {
                     break;
diff --git a/components/bt/host/bluedroid/stack/l2cap/l2c_main.c b/components/bt/host/bluedroid/stack/l2cap/l2c_main.c
index e50e59dce..c6baaca3c 100644
--- a/components/bt/host/bluedroid/stack/l2cap/l2c_main.c
+++ b/components/bt/host/bluedroid/stack/l2cap/l2c_main.c
@@ -883,6 +883,9 @@ void l2c_init (void)
     if (l2cb.rcv_pending_q == NULL) {
         L2CAP_TRACE_ERROR("%s unable to allocate memory for link layer control block", __func__);
     }
+#if BLE_INCLUDED == TRUE
+    l2ble_update_att_acl_pkt_num(L2CA_BUFF_INI, NULL);
+#endif
 }
 
 void l2c_free(void)
@@ -892,6 +895,9 @@ void l2c_free(void)
 #if L2C_DYNAMIC_MEMORY
     FREE_AND_RESET(l2c_cb_ptr);
 #endif
+#if BLE_INCLUDED == TRUE
+    l2ble_update_att_acl_pkt_num(L2CA_BUFF_DEINIT, NULL);
+#endif
 }
 
 /*******************************************************************************
diff --git a/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c b/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c
index cd886bbfe..01761346a 100644
--- a/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c
+++ b/components/bt/host/bluedroid/stack/l2cap/l2c_utils.c
@@ -3662,7 +3662,7 @@ void l2cu_check_channel_congestion (tL2C_CCB *p_ccb)
         } else {
             tL2C_LCB *p_lcb = p_ccb->p_lcb;
             /* If this channel was not congested but it is congested now, tell the app */
-            if ((q_count > p_ccb->buff_quota) || (p_lcb && (p_ccb->local_cid == L2CAP_ATT_CID) && (p_lcb->link_xmit_quota > 0) && (p_lcb->link_xmit_quota <= p_lcb->sent_not_acked))) {
+            if (q_count > p_ccb->buff_quota || (p_lcb && (p_lcb->link_xmit_data_q) && (list_length(p_lcb->link_xmit_data_q) + q_count) > p_ccb->buff_quota)) {
                 p_ccb->cong_sent = TRUE;
                 if (p_ccb->p_rcb && p_ccb->p_rcb->api.pL2CA_CongestionStatus_Cb) {
                     L2CAP_TRACE_DEBUG ("L2CAP - Calling CongestionStatus_Cb (TRUE),CID:0x%04x,XmitQ:%u,Quota:%u",
diff --git a/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_client/main/example_ble_client_throughput.c b/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_client/main/example_ble_client_throughput.c
index 92387b62b..60a3774cc 100644
--- a/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_client/main/example_ble_client_throughput.c
+++ b/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_client/main/example_ble_client_throughput.c
@@ -504,7 +504,7 @@ static void throughput_client_task(void *param)
                 assert(res == pdTRUE);
             } else {
                 if (is_connect) {
-                    int free_buff_num = esp_ble_get_sendable_packets_num();
+                    int free_buff_num = esp_ble_get_cur_sendable_packets_num(gl_profile_tab[PROFILE_A_APP_ID].conn_id);
                     if(free_buff_num > 0) {
                         for( ; free_buff_num > 0; free_buff_num--) {
                             // the app data set to 490 just for divided into two packages to send in the low layer
diff --git a/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_server/main/example_ble_server_throughput.c b/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_server/main/example_ble_server_throughput.c
index 5d2ebeb83..5b75ca0fe 100644
--- a/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_server/main/example_ble_server_throughput.c
+++ b/examples/bluetooth/bluedroid/ble/ble_throughput/throughput_server/main/example_ble_server_throughput.c
@@ -624,7 +624,7 @@ void throughput_server_task(void *param)
             assert(res == pdTRUE);
         } else {
             if (is_connect) {
-                int free_buff_num = esp_ble_get_sendable_packets_num();
+                int free_buff_num = esp_ble_get_cur_sendable_packets_num(gl_profile_tab[PROFILE_A_APP_ID].conn_id);
                 if(free_buff_num > 0) {
                     for( ; free_buff_num > 0; free_buff_num--) {
                         esp_ble_gatts_send_indicate(gl_profile_tab[PROFILE_A_APP_ID].gatts_if, gl_profile_tab[PROFILE_A_APP_ID].conn_id,