diff --git a/.changelog/3613.txt b/.changelog/3613.txt
new file mode 100644
index 0000000000..d3262e28a8
--- /dev/null
+++ b/.changelog/3613.txt
@@ -0,0 +1,3 @@
+```release-note:enhancement
+datasource/tencentcloud_instances: modify the length of the instance name to 128
+```
\ No newline at end of file
diff --git a/tencentcloud/services/cvm/data_source_tc_instances.go b/tencentcloud/services/cvm/data_source_tc_instances.go
index f0c41fc89b..8e63687afe 100644
--- a/tencentcloud/services/cvm/data_source_tc_instances.go
+++ b/tencentcloud/services/cvm/data_source_tc_instances.go
@@ -27,7 +27,7 @@ func DataSourceTencentCloudInstances() *schema.Resource {
 			"instance_name": {
 				Type:         schema.TypeString,
 				Optional:     true,
-				ValidateFunc: tccommon.ValidateStringLengthInRange(1, 30),
+				ValidateFunc: tccommon.ValidateStringLengthInRange(1, 128),
 				Description:  "Name of the instances to be queried.",
 			},
 			"availability_zone": {
diff --git a/tencentcloud/services/cvm/data_source_tc_instances_set.go b/tencentcloud/services/cvm/data_source_tc_instances_set.go
index 4f964a74bf..ef986dec05 100644
--- a/tencentcloud/services/cvm/data_source_tc_instances_set.go
+++ b/tencentcloud/services/cvm/data_source_tc_instances_set.go
@@ -26,7 +26,7 @@ func DataSourceTencentCloudInstancesSet() *schema.Resource {
 			"instance_name": {
 				Type:         schema.TypeString,
 				Optional:     true,
-				ValidateFunc: tccommon.ValidateStringLengthInRange(1, 30),
+				ValidateFunc: tccommon.ValidateStringLengthInRange(1, 128),
 				Description:  "Name of the instances to be queried.",
 			},
 			"availability_zone": {