diff --git a/ppocr/data/lmdb_dataset.py b/ppocr/data/lmdb_dataset.py
index 3a51cefec2f1da2c96cceb6482d8303aa136b78a..295643e401481d30cf433346727f39d4a4c7d2f4 100644
--- a/ppocr/data/lmdb_dataset.py
+++ b/ppocr/data/lmdb_dataset.py
@@ -40,6 +40,8 @@ class LMDBDataSet(Dataset):
         if self.do_shuffle:
             np.random.shuffle(self.data_idx_order_list)
         self.ops = create_operators(dataset_config['transforms'], global_config)
+        self.ext_op_transform_idx = dataset_config.get("ext_op_transform_idx",
+                                                       1)
 
         ratio_list = dataset_config.get("ratio_list", [1.0])
         self.need_reset = True in [x < 1 for x in ratio_list]
@@ -92,6 +94,32 @@ class LMDBDataSet(Dataset):
             return None
         return imgori
 
+    def get_ext_data(self):
+        ext_data_num = 0
+        for op in self.ops:
+            if hasattr(op, 'ext_data_num'):
+                ext_data_num = getattr(op, 'ext_data_num')
+                break
+        load_data_ops = self.ops[:self.ext_op_transform_idx]
+        ext_data = []
+
+        while len(ext_data) < ext_data_num:
+            lmdb_idx, file_idx = self.data_idx_order_list[np.random.randint(
+                len(self))]
+            lmdb_idx = int(lmdb_idx)
+            file_idx = int(file_idx)
+            sample_info = self.get_lmdb_sample_info(
+                self.lmdb_sets[lmdb_idx]['txn'], file_idx)
+            if sample_info is None:
+                continue
+            img, label = sample_info
+            data = {'image': img, 'label': label}
+            data = transform(data, load_data_ops)
+            if data is None:
+                continue
+            ext_data.append(data)
+        return ext_data
+
     def get_lmdb_sample_info(self, txn, index):
         label_key = 'label-%09d'.encode() % index
         label = txn.get(label_key)
@@ -112,6 +140,7 @@ class LMDBDataSet(Dataset):
             return self.__getitem__(np.random.randint(self.__len__()))
         img, label = sample_info
         data = {'image': img, 'label': label}
+        data['ext_data'] = self.get_ext_data()
         outs = transform(data, self.ops)
         if outs is None:
             return self.__getitem__(np.random.randint(self.__len__()))