From 0905a97c511b47d8947eda2cb3474e29335024d8 Mon Sep 17 00:00:00 2001
From: SevenEarth <391613297@qq.com>
Date: Tue, 17 Jun 2025 19:22:56 +0800
Subject: [PATCH 1/2] add

---
 .../services/clb/resource_tc_clb_instance.go     | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/tencentcloud/services/clb/resource_tc_clb_instance.go b/tencentcloud/services/clb/resource_tc_clb_instance.go
index b0b2b04513..3c99c23323 100644
--- a/tencentcloud/services/clb/resource_tc_clb_instance.go
+++ b/tencentcloud/services/clb/resource_tc_clb_instance.go
@@ -338,9 +338,9 @@ func resourceTencentCloudClbInstanceCreate(d *schema.ResourceData, meta interfac
 	if v, ok := d.Get("snat_ips").([]interface{}); ok && len(v) > 0 {
 		for i := range v {
 			item := v[i].(map[string]interface{})
-			subnetId := item["subnet_id"].(string)
-			snatIp := &clb.SnatIp{
-				SubnetId: &subnetId,
+			snatIp := &clb.SnatIp{}
+			if v, ok := item["subnet_id"].(string); ok && v != "" {
+				snatIp.SubnetId = &v
 			}
 
 			if v, ok := item["ip"].(string); ok && v != "" {
@@ -470,8 +470,9 @@ func resourceTencentCloudClbInstanceCreate(d *schema.ResourceData, meta interfac
 		sgRequest.SecurityGroups = make([]*string, 0, len(securityGroups))
 		for i := range securityGroups {
 			if securityGroups[i] != nil {
-				securityGroup := securityGroups[i].(string)
-				sgRequest.SecurityGroups = append(sgRequest.SecurityGroups, &securityGroup)
+				if securityGroup, ok := securityGroups[i].(string); ok && securityGroup != "" {
+					sgRequest.SecurityGroups = append(sgRequest.SecurityGroups, &securityGroup)
+				}
 			}
 		}
 
@@ -891,8 +892,9 @@ func resourceTencentCloudClbInstanceUpdate(d *schema.ResourceData, meta interfac
 		securityGroups := d.Get("security_groups").([]interface{})
 		sgRequest.SecurityGroups = make([]*string, 0, len(securityGroups))
 		for i := range securityGroups {
-			securityGroup := securityGroups[i].(string)
-			sgRequest.SecurityGroups = append(sgRequest.SecurityGroups, &securityGroup)
+			if securityGroup, ok := securityGroups[i].(string); ok && securityGroup != "" {
+				sgRequest.SecurityGroups = append(sgRequest.SecurityGroups, &securityGroup)
+			}
 		}
 
 		err := resource.Retry(tccommon.WriteRetryTimeout, func() *resource.RetryError {

From 8712f7580f0a2fd0a81cec37e6baa3fadf9c39c1 Mon Sep 17 00:00:00 2001
From: SevenEarth <391613297@qq.com>
Date: Tue, 17 Jun 2025 19:24:50 +0800
Subject: [PATCH 2/2] add

---
 .changelog/3415.txt | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 .changelog/3415.txt

diff --git a/.changelog/3415.txt b/.changelog/3415.txt
new file mode 100644
index 0000000000..12fb2b56ad
--- /dev/null
+++ b/.changelog/3415.txt
@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/tencentcloud_clb_instance: optmize `security_groups` nil value
+```