diff --git a/oss-dal/src/main/java/cn/axzo/oss/dal/entity/File.java b/oss-dal/src/main/java/cn/axzo/oss/dal/entity/File.java
index 4e58632..16a14b8 100644
--- a/oss-dal/src/main/java/cn/axzo/oss/dal/entity/File.java
+++ b/oss-dal/src/main/java/cn/axzo/oss/dal/entity/File.java
@@ -7,6 +7,8 @@ import java.util.Date;
 import com.baomidou.mybatisplus.annotation.TableId;
 import com.baomidou.mybatisplus.annotation.TableField;
 import java.io.Serializable;
+import java.util.Objects;
+
 import lombok.Data;
 import lombok.EqualsAndHashCode;
 import lombok.experimental.Accessors;
@@ -149,4 +151,21 @@ public class File extends Model<File> {
         return this.id;
     }
 
+    public Long fetchFileSize() {
+        if (Objects.isNull(this.getStorageSize()) || Objects.isNull(this.getStorageUnit())) {
+            return 0L;
+        }
+
+        if (this.getStorageUnit().equalsIgnoreCase("b")) {
+            return this.getStorageSize().longValue();
+        }
+        if (this.getStorageUnit().equalsIgnoreCase("kb")) {
+            return this.getStorageSize().longValue() * 1024L;
+        }
+        if (this.getStorageUnit().equalsIgnoreCase("mb")) {
+            return this.getStorageSize().longValue() * 1024 * 1024L;
+        }
+        return 0L;
+    }
+
 }
diff --git a/oss-http-api/src/main/java/cn/axzo/oss/http/model/ApiSignUrlDownloadResponse.java b/oss-http-api/src/main/java/cn/axzo/oss/http/model/ApiSignUrlDownloadResponse.java
index 4796a26..9a2cbe5 100644
--- a/oss-http-api/src/main/java/cn/axzo/oss/http/model/ApiSignUrlDownloadResponse.java
+++ b/oss-http-api/src/main/java/cn/axzo/oss/http/model/ApiSignUrlDownloadResponse.java
@@ -29,4 +29,9 @@ public class ApiSignUrlDownloadResponse {
      */
     private String fileName;
 
+    /**
+     * 文件大小
+     */
+    private Long fileSize;
+
 }
diff --git a/oss-manager-api/src/main/java/cn/axzo/oss/manager/api/dto/response/SignUrlDownloadResponse.java b/oss-manager-api/src/main/java/cn/axzo/oss/manager/api/dto/response/SignUrlDownloadResponse.java
index 538a1a8..3860b4b 100644
--- a/oss-manager-api/src/main/java/cn/axzo/oss/manager/api/dto/response/SignUrlDownloadResponse.java
+++ b/oss-manager-api/src/main/java/cn/axzo/oss/manager/api/dto/response/SignUrlDownloadResponse.java
@@ -30,4 +30,9 @@ public class SignUrlDownloadResponse {
      */
     private String fileName;
 
+    /**
+     * 文件大小
+     */
+    private Long fileSize;
+
 }
diff --git a/oss-service/src/main/java/cn/axzo/oss/service/impl/FileServiceImpl.java b/oss-service/src/main/java/cn/axzo/oss/service/impl/FileServiceImpl.java
index 9a2c410..9352089 100644
--- a/oss-service/src/main/java/cn/axzo/oss/service/impl/FileServiceImpl.java
+++ b/oss-service/src/main/java/cn/axzo/oss/service/impl/FileServiceImpl.java
@@ -981,6 +981,7 @@ public class FileServiceImpl implements FileService {
                             .signUrl(this.fileManager.buildPublicXImageProcess(url, style))
                             .fileKey(item.getFileUuid())
                             .fileName(item.getFileName())
+                            .fileSize(item.fetchFileSize())
                             .build();
                 case PRIVATE_BUCKET://私有桶 - 临时授权链接 例如 http://xxx.png?Expire=a&AccessKeyId=b&Signature=c&repsonse-content-disposition=d
                     String signUrl = this.fileManager.signUrlDownload(item.getBucketName(), tgtFileKey, Objects.nonNull(expire) ? expire : SIGN_URL_DOWNLOAD_EXPIRE_SECOND , item.getChannelCode(), item.getFileName(), style, hasFileName);
@@ -988,6 +989,7 @@ public class FileServiceImpl implements FileService {
                             .signUrl(UrlUtil.httpToHttps(signUrl))
                             .fileKey(item.getFileUuid())
                             .fileName(item.getFileName())
+                            .fileSize(item.fetchFileSize())
                             .build();
                 default:
                     BizException.error(CodeEnum.CHANNEL_TYPE_NOT_EXIST);