diff --git a/Cargo.lock b/Cargo.lock
index 125e137..aac15ba 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1473,6 +1473,7 @@ dependencies = [
  "sentry",
  "serde",
  "serde_json",
+ "serde_urlencoded",
  "serde_variant",
  "sha2",
  "sqlx",
diff --git a/Cargo.toml b/Cargo.toml
index e379dde..2cc5dd4 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,6 +10,7 @@ path = "src/main.rs"
 [dependencies]
 serde = { version = "1.0.228", features = [ "derive" ] }
 serde_json = "1.0.149"
+serde_urlencoded = "0.7.1"
 tokio = { version = "1.49.0", features = [
   "signal",
   "rt-multi-thread",
diff --git a/src/aliyun/cdn.rs b/src/aliyun/cdn.rs
index 43c962d..d1b7aef 100644
--- a/src/aliyun/cdn.rs
+++ b/src/aliyun/cdn.rs
@@ -119,6 +119,20 @@ pub struct RefreshObjectCachesRequest {
     pub force: Option<bool>,
 }
 
+/// Form parameters for RefreshObjectCaches API
+/// This struct is used for URL encoding the request body
+#[derive(Debug, Clone, Serialize)]
+struct RefreshObjectCachesFormParams {
+    #[serde(rename = "ObjectPath")]
+    object_path: String,
+
+    #[serde(rename = "ObjectType", skip_serializing_if = "Option::is_none")]
+    object_type: Option<String>,
+
+    #[serde(rename = "Force", skip_serializing_if = "Option::is_none")]
+    force: Option<bool>,
+}
+
 /// Response from RefreshObjectCaches API
 #[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
 pub struct RefreshObjectCachesResponse {
@@ -257,17 +271,14 @@ impl AliyunCdnClient {
     ) -> AppResult<RefreshObjectCachesResponse> {
         // RefreshObjectCaches is a POST request with parameters in an HTML form body.
         // Reference: https://help.aliyun.com/zh/cdn/developer-reference/api-cdn-2018-05-10-refreshobjectcaches
-        let mut form_params = BTreeMap::new();
-        form_params.insert("ObjectPath".to_string(), request.object_path.clone());
-
-        if let Some(ref object_type) = request.object_type {
-            form_params.insert("ObjectType".to_string(), object_type.clone());
-        }
-        if let Some(force) = request.force {
-            form_params.insert("Force".to_string(), force.to_string());
-        }
+        let form_params = RefreshObjectCachesFormParams {
+            object_path: request.object_path.clone(),
+            object_type: request.object_type.clone(),
+            force: request.force,
+        };
 
-        let form_body = build_form_urlencoded_body(&form_params);
+        let form_body = serde_urlencoded::to_string(&form_params)
+            .context("Failed to encode form parameters")?;
 
         // Sign the request (ACS3-HMAC-SHA256). For this API, the form body must be included
         // in the body hash, so keep the canonical query empty.
@@ -327,29 +338,3 @@ impl AliyunCdnClient {
         Ok(result)
     }
 }
-
-fn build_form_urlencoded_body(params: &BTreeMap<String, String>) -> String {
-    params
-        .iter()
-        .map(|(k, v)| format!("{}={}", form_urlencode(k), form_urlencode(v)))
-        .collect::<Vec<_>>()
-        .join("&")
-}
-
-// application/x-www-form-urlencoded encoding.
-// - Space becomes '+'
-// - Unreserved characters are not escaped
-// - Everything else is percent-encoded with upper-case hex
-fn form_urlencode(input: &str) -> String {
-    let mut out = String::with_capacity(input.len());
-    for &b in input.as_bytes() {
-        match b {
-            b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
-                out.push(b as char)
-            }
-            b' ' => out.push('+'),
-            _ => out.push_str(&format!("%{:02X}", b)),
-        }
-    }
-    out
-}