diff --git a/src/traverseFileTree.ts b/src/traverseFileTree.ts
index 06665d3c..4c1f644f 100644
--- a/src/traverseFileTree.ts
+++ b/src/traverseFileTree.ts
@@ -10,33 +10,36 @@ interface InternalDataTransferItem extends DataTransferItem {
   path: string;
 }
 
-function loopFiles(item: InternalDataTransferItem, callback) {
-  const dirReader = item.createReader();
-  let fileList = [];
-
-  function sequence() {
-    dirReader.readEntries((entries: InternalDataTransferItem[]) => {
-      const entryList = Array.prototype.slice.apply(entries);
-      fileList = fileList.concat(entryList);
+const traverseFileTree = (files: InternalDataTransferItem[], callback, isAccepted) => {
+  let restFile = files.length;
+  const flattenFileList = [];
+  function loopFiles(item: InternalDataTransferItem, InnerCallback) {
+    const dirReader = item.createReader();
+    let fileList = [];
 
-      // Check if all the file has been viewed
-      const isFinished = !entryList.length;
+    function sequence() {
+      dirReader.readEntries((entries: InternalDataTransferItem[]) => {
+        const entryList = Array.prototype.slice.apply(entries);
+        fileList = fileList.concat(entryList);
 
-      if (isFinished) {
-        callback(fileList);
-      } else {
-        sequence();
-      }
-    });
-  }
+        // Check if all the file has been viewed
+        const isFinished = !entryList.length;
 
-  sequence();
-}
+        if (isFinished) {
+          restFile = restFile - 1 + fileList.length;
+          InnerCallback(fileList);
+        } else {
+          sequence();
+        }
+      });
+    }
 
-const traverseFileTree = (files: InternalDataTransferItem[], callback, isAccepted) => {
+    sequence();
+  }
   // eslint-disable-next-line @typescript-eslint/naming-convention
   const _traverseFileTree = (item: InternalDataTransferItem, path?: string) => {
     if (!item) {
+      restFile = restFile - 1;
       return;
     }
     // eslint-disable-next-line no-param-reassign
@@ -59,7 +62,11 @@ const traverseFileTree = (files: InternalDataTransferItem[], callback, isAccepte
               },
             });
           }
-          callback([file]);
+          flattenFileList.push(file);
+          restFile = restFile - 1;
+          if (restFile === 0) {
+            callback(flattenFileList);
+          }
         }
       });
     } else if (item.isDirectory) {
diff --git a/tests/uploader.spec.tsx b/tests/uploader.spec.tsx
index b7e060cd..df7749cb 100644
--- a/tests/uploader.spec.tsx
+++ b/tests/uploader.spec.tsx
@@ -25,7 +25,7 @@ const makeFileSystemEntry = item => {
       return {
         readEntries(handle) {
           if (!first) {
-            return [];
+            return handle([]);
           }
 
           first = false;
@@ -374,6 +374,56 @@ describe('uploader', () => {
       uploader = render(<Upload {...props} />);
     });
 
+    it('beforeUpload should run after all children files are parsed', done => {
+      const props = { action: '/test', directory: true, accept: '.png' };
+      const mockBeforeUpload = jest.fn();
+      const beforeUpload = (file, fileList) => {
+        console.log('beforeUpload', file, fileList);
+        mockBeforeUpload(file, fileList);
+      };
+      const Test = () => {
+        return <Upload {...props} beforeUpload={beforeUpload} />;
+      };
+
+      const { container } = render(<Test />);
+      const files = {
+        name: 'foo',
+        children: [
+          {
+            name: 'bar',
+            children: [
+              {
+                name: '1.png',
+              },
+              {
+                name: '2.png',
+              },
+              {
+                name: 'rc',
+                children: [
+                  {
+                    name: '3.png',
+                  },
+                  {
+                    name: '4.png',
+                  },
+                ],
+              },
+            ],
+          },
+        ],
+      };
+      const input = container.querySelector('input')!;
+      fireEvent.drop(input, { dataTransfer: { items: [makeDataTransferItem(files)] } });
+      setTimeout(() => {
+        expect(mockBeforeUpload.mock.calls.length).toBe(4);
+        expect(mockBeforeUpload.mock.calls[0][1].length).toBe(4);
+        expect(mockBeforeUpload.mock.calls[1][1].length).toBe(4);
+        expect(mockBeforeUpload.mock.calls[2][1].length).toBe(4);
+        expect(mockBeforeUpload.mock.calls[3][1].length).toBe(4);
+        done();
+      }, 100);
+    });
     it('unaccepted type files to upload will not trigger onStart', done => {
       const input = uploader.container.querySelector('input')!;
       const files = {