diff --git a/client/packages/lowcoder/src/util/fileUtils.ts b/client/packages/lowcoder/src/util/fileUtils.ts
index 647122596..7b98e21ff 100644
--- a/client/packages/lowcoder/src/util/fileUtils.ts
+++ b/client/packages/lowcoder/src/util/fileUtils.ts
@@ -48,7 +48,7 @@ export async function saveDataAsFile({ data, filename, fileType, dataType }: Sav
 
   if (dataType === "base64") {
     const blob = new Blob([Buffer.from(data, "base64")], {
-      type: mime + ";charset=utf-16",
+      type: mim + ";charset=utf-16",
     });
     return saveAs(blob, filename, { autoBom: true });
   }
diff --git a/docs/build-apps/write-javascript/built-in-javascript-functions.md b/docs/build-apps/write-javascript/built-in-javascript-functions.md
index 0bbbb6db0..777f01f2e 100644
--- a/docs/build-apps/write-javascript/built-in-javascript-functions.md
+++ b/docs/build-apps/write-javascript/built-in-javascript-functions.md
@@ -81,7 +81,7 @@ utils.downloadFile(query1.data, "users-data.xlsx")
 
 // Example: Download the results of query1 as a XLXS file named users-data.
 utils.downloadFile(restApiQuery.data, "users-data", {
-  fileType: "pdf",
+  fileType: "xlsx",
   dataType: "base64",
 })
 ```
diff --git a/server/api-service/lowcoder-plugins/restApiPlugin/src/main/java/org/lowcoder/plugin/restapi/RestApiExecutor.java b/server/api-service/lowcoder-plugins/restApiPlugin/src/main/java/org/lowcoder/plugin/restapi/RestApiExecutor.java
index 84d053e62..9f3eaf122 100644
--- a/server/api-service/lowcoder-plugins/restApiPlugin/src/main/java/org/lowcoder/plugin/restapi/RestApiExecutor.java
+++ b/server/api-service/lowcoder-plugins/restApiPlugin/src/main/java/org/lowcoder/plugin/restapi/RestApiExecutor.java
@@ -426,7 +426,7 @@ private ResponseBodyData parseResponseDataInfo(byte[] body, MediaType contentTyp
         }
         if (isBinary(contentType)) {
             return ResponseBodyData.builder()
-                    .body(Base64.getEncoder().encode(body))
+                    .body(body)
                     .dataType(ResponseDataType.BINARY)
                     .build();
         }