diff --git a/.changelog/3385.txt b/.changelog/3385.txt
new file mode 100644
index 0000000000..002a5e3c16
--- /dev/null
+++ b/.changelog/3385.txt
@@ -0,0 +1,3 @@
+```release-note:enhancement
+resource/tencentcloud_ccn: update params
+```
diff --git a/tencentcloud/services/ccn/resource_tc_ccn.go b/tencentcloud/services/ccn/resource_tc_ccn.go
index 7b1e719b93..7ae73d01e2 100644
--- a/tencentcloud/services/ccn/resource_tc_ccn.go
+++ b/tencentcloud/services/ccn/resource_tc_ccn.go
@@ -73,14 +73,14 @@ func ResourceTencentCloudCcn() *schema.Resource {
 			"route_ecmp_flag": {
 				Type:        schema.TypeBool,
 				Optional:    true,
-				Default:     false,
-				Description: "Whether to enable the equivalent routing function. `true`: enabled, `false`: disabled.",
+				Computed:    true,
+				Description: "Whether to enable the equivalent routing function. `true`: enabled, `false`: disabled. Default is false.",
 			},
 			"route_overlap_flag": {
 				Type:        schema.TypeBool,
 				Optional:    true,
-				Default:     false,
-				Description: "Whether to enable the routing overlap function. `true`: enabled, `false`: disabled.",
+				Computed:    true,
+				Description: "Whether to enable the routing overlap function. `true`: enabled, `false`: disabled. Default is true, cannot set to false.",
 			},
 			"tags": {
 				Type:        schema.TypeMap,
@@ -158,36 +158,48 @@ func resourceTencentCloudCcnCreate(d *schema.ResourceData, meta interface{}) err
 	}
 
 	// set ECMP/Overlap
-	request := vpc.NewModifyCcnAttributeRequest()
-	request.CcnId = &info.ccnId
+	var (
+		hasRouteECMP     bool
+		hasRouteOverlap  bool
+		routeECMPFlag    bool
+		routeOverlapFlag bool
+	)
+
 	if temp, ok := d.GetOkExists("route_ecmp_flag"); ok {
-		request.RouteECMPFlag = helper.Bool(temp.(bool))
+		routeECMPFlag = temp.(bool)
+		hasRouteECMP = true
 	}
 
 	if temp, ok := d.GetOkExists("route_overlap_flag"); ok {
-		request.RouteOverlapFlag = helper.Bool(temp.(bool))
+		routeOverlapFlag = temp.(bool)
+		hasRouteOverlap = true
 	}
 
-	err = resource.Retry(tccommon.WriteRetryTimeout, func() *resource.RetryError {
-		result, e := meta.(tccommon.ProviderMeta).GetAPIV3Conn().UseVpcClient().ModifyCcnAttribute(request)
-		if e != nil {
-			return tccommon.RetryError(e)
-		} else {
-			log.Printf("[DEBUG]%s api[%s] success, request body [%s], response body [%s]\n", logId, request.GetAction(), request.ToJsonString(), result.ToJsonString())
-		}
+	if hasRouteECMP || hasRouteOverlap {
+		request := vpc.NewModifyCcnAttributeRequest()
+		request.CcnId = &info.ccnId
+		request.RouteECMPFlag = helper.Bool(routeECMPFlag)
+		request.RouteOverlapFlag = helper.Bool(routeOverlapFlag)
+		err = resource.Retry(tccommon.WriteRetryTimeout, func() *resource.RetryError {
+			result, e := meta.(tccommon.ProviderMeta).GetAPIV3Conn().UseVpcClient().ModifyCcnAttribute(request)
+			if e != nil {
+				return tccommon.RetryError(e)
+			} else {
+				log.Printf("[DEBUG]%s api[%s] success, request body [%s], response body [%s]\n", logId, request.GetAction(), request.ToJsonString(), result.ToJsonString())
+			}
 
-		if result == nil {
-			e = fmt.Errorf("update ModifyCcnAttribute failed")
-			return resource.NonRetryableError(e)
-		}
+			if result == nil {
+				e = fmt.Errorf("update ModifyCcnAttribute failed")
+				return resource.NonRetryableError(e)
+			}
 
-		_ = result
-		return nil
-	})
+			return nil
+		})
 
-	if err != nil {
-		log.Printf("[CRITAL]%s update ModifyCcnAttribute failed, reason:%s\n", logId, err.Error())
-		return err
+		if err != nil {
+			log.Printf("[CRITAL]%s update ModifyCcnAttribute failed, reason:%s\n", logId, err.Error())
+			return err
+		}
 	}
 
 	return resourceTencentCloudCcnRead(d, meta)
diff --git a/tencentcloud/services/ccn/resource_tc_ccn.md b/tencentcloud/services/ccn/resource_tc_ccn.md
index 13a65c5b51..05598bc09c 100644
--- a/tencentcloud/services/ccn/resource_tc_ccn.md
+++ b/tencentcloud/services/ccn/resource_tc_ccn.md
@@ -1,8 +1,10 @@
 Provides a resource to create a CCN instance.
 
+~> **NOTE:** `route_overlap_flag` currently does not support setting to `false`.
+
 Example Usage
 
-Create a prepaid CCN
+Create a PREPAID CCN
 
 ```hcl
 resource "tencentcloud_ccn" "example" {
@@ -14,12 +16,12 @@ resource "tencentcloud_ccn" "example" {
   route_ecmp_flag      = true
   route_overlap_flag   = true
   tags = {
-    createBy = "terraform"
+    createBy = "Terraform"
   }
 }
 ```
 
-Create a post-paid regional export speed limit type CCN
+Create a POSTPAID regional export speed limit type CCN
 
 ```hcl
 resource "tencentcloud_ccn" "example" {
@@ -29,14 +31,14 @@ resource "tencentcloud_ccn" "example" {
   charge_type          = "POSTPAID"
   bandwidth_limit_type = "OUTER_REGION_LIMIT"
   route_ecmp_flag      = false
-  route_overlap_flag   = false
+  route_overlap_flag   = true
   tags = {
-    createBy = "terraform"
+    createBy = "Terraform"
   }
 }
 ```
 
-Create a post-paid inter-regional rate limit type CNN
+Create a POSTPAID inter-regional rate limit type CNN
 
 ```hcl
 resource "tencentcloud_ccn" "example" {
diff --git a/website/docs/r/ccn.html.markdown b/website/docs/r/ccn.html.markdown
index 7366a7fa4b..75fb447593 100644
--- a/website/docs/r/ccn.html.markdown
+++ b/website/docs/r/ccn.html.markdown
@@ -11,9 +11,11 @@ description: |-
 
 Provides a resource to create a CCN instance.
 
+~> **NOTE:** `route_overlap_flag` currently does not support setting to `false`.
+
 ## Example Usage
 
-### Create a prepaid CCN
+### Create a PREPAID CCN
 
 ```hcl
 resource "tencentcloud_ccn" "example" {
@@ -25,12 +27,12 @@ resource "tencentcloud_ccn" "example" {
   route_ecmp_flag      = true
   route_overlap_flag   = true
   tags = {
-    createBy = "terraform"
+    createBy = "Terraform"
   }
 }
 ```
 
-### Create a post-paid regional export speed limit type CCN
+### Create a POSTPAID regional export speed limit type CCN
 
 ```hcl
 resource "tencentcloud_ccn" "example" {
@@ -40,14 +42,14 @@ resource "tencentcloud_ccn" "example" {
   charge_type          = "POSTPAID"
   bandwidth_limit_type = "OUTER_REGION_LIMIT"
   route_ecmp_flag      = false
-  route_overlap_flag   = false
+  route_overlap_flag   = true
   tags = {
-    createBy = "terraform"
+    createBy = "Terraform"
   }
 }
 ```
 
-### Create a post-paid inter-regional rate limit type CNN
+### Create a POSTPAID inter-regional rate limit type CNN
 
 ```hcl
 resource "tencentcloud_ccn" "example" {
@@ -68,8 +70,8 @@ The following arguments are supported:
 * `charge_type` - (Optional, String, ForceNew) Billing mode. Valid values: `PREPAID`, `POSTPAID`. `PREPAID` means prepaid, which means annual and monthly subscription, `POSTPAID` means post-payment, which means billing by volume. The default is `POSTPAID`. The prepaid model only supports inter-regional speed limit, and the post-paid model supports inter-regional speed limit and regional export speed limit.
 * `description` - (Optional, String) Description of CCN, and maximum length does not exceed 100 bytes.
 * `qos` - (Optional, String, ForceNew) CCN service quality, 'PT': Platinum, 'AU': Gold, 'AG': Silver. The default is 'AU'.
-* `route_ecmp_flag` - (Optional, Bool) Whether to enable the equivalent routing function. `true`: enabled, `false`: disabled.
-* `route_overlap_flag` - (Optional, Bool) Whether to enable the routing overlap function. `true`: enabled, `false`: disabled.
+* `route_ecmp_flag` - (Optional, Bool) Whether to enable the equivalent routing function. `true`: enabled, `false`: disabled. Default is false.
+* `route_overlap_flag` - (Optional, Bool) Whether to enable the routing overlap function. `true`: enabled, `false`: disabled. Default is true, cannot set to false.
 * `tags` - (Optional, Map) Instance tag.
 
 ## Attributes Reference