diff --git a/mmocr/datasets/kie_dataset.py b/mmocr/datasets/kie_dataset.py
index b77927cf..6d1febcd 100644
--- a/mmocr/datasets/kie_dataset.py
+++ b/mmocr/datasets/kie_dataset.py
@@ -1,6 +1,7 @@
 import copy
 from os import path as osp
 
+import mmcv
 import numpy as np
 import torch
 
@@ -47,14 +48,13 @@ class KIEDataset(BaseDataset):
 
         self.norm = norm
         self.directed = directed
-
-        self.dict = dict({'': 0})
-        with open(dict_file, 'r') as fr:
-            idx = 1
-            for line in fr:
-                char = line.strip()
-                self.dict[char] = idx
-                idx += 1
+        self.dict = {
+            '': 0,
+            **{
+                line.rstrip('\r\n'): ind
+                for ind, line in enumerate(mmcv.list_from_file(dict_file), 1)
+            }
+        }
 
     def pre_pipeline(self, results):
         results['img_prefix'] = self.img_prefix
@@ -70,7 +70,7 @@ class KIEDataset(BaseDataset):
             dict: A dict containing the following keys:
 
                 - bboxes (np.ndarray): Bbox in one image with shape:
-                    box_num * 4.
+                    box_num * 4. They are sorted clockwise when loading.
                 - relations (np.ndarray): Relations between bbox with shape:
                     box_num * box_num * D.
                 - texts (np.ndarray): Text index with shape:
@@ -93,7 +93,7 @@ class KIEDataset(BaseDataset):
             texts.append(ann['text'])
             text_ind = [self.dict[c] for c in text if c in self.dict]
             text_inds.append(text_ind)
-            labels.append(ann['label'])
+            labels.append(ann.get('label', 0))
             edges.append(ann.get('edge', 0))
 
         ann_infos = dict(
@@ -201,13 +201,13 @@ class KIEDataset(BaseDataset):
 
     def compute_relation(self, boxes):
         """Compute relation between every two boxes."""
-        x1s, y1s = boxes[:, 0:1], boxes[:, 1:2]
-        x2s, y2s = boxes[:, 4:5], boxes[:, 5:6]
-        ws, hs = x2s - x1s + 1, np.maximum(y2s - y1s + 1, 1)
-        dxs = (x1s[:, 0][None] - x1s) / self.norm
-        dys = (y1s[:, 0][None] - y1s) / self.norm
-        xhhs, xwhs = hs[:, 0][None] / hs, ws[:, 0][None] / hs
-        whs = ws / hs + np.zeros_like(xhhs)
-        relations = np.stack([dxs, dys, whs, xhhs, xwhs], -1)
-        bboxes = np.concatenate([x1s, y1s, x2s, y2s], -1).astype(np.float32)
-        return relations, bboxes
+        x1, y1 = boxes[:, 0:1], boxes[:, 1:2]
+        x2, y2 = boxes[:, 4:5], boxes[:, 5:6]
+        w, h = np.maximum(x2 - x1 + 1, 1), np.maximum(y2 - y1 + 1, 1)
+        dx = (x1.T - x1) / self.norm
+        dy = (y1.T - y1) / self.norm
+        xhh, xwh = h.T / h, w.T / h
+        whs = w / h + np.zeros_like(xhh)
+        relation = np.stack([dx, dy, whs, xhh, xwh], -1)
+        bboxes = np.concatenate([x1, y1, x2, y2], -1).astype(np.float32)
+        return relation, bboxes
diff --git a/mmocr/datasets/utils/loader.py b/mmocr/datasets/utils/loader.py
index 55a4d075..0cc95366 100644
--- a/mmocr/datasets/utils/loader.py
+++ b/mmocr/datasets/utils/loader.py
@@ -1,5 +1,7 @@
 import os.path as osp
 
+import mmcv
+
 from mmocr.datasets.builder import LOADERS, build_parser
 
 
@@ -47,13 +49,7 @@ class HardDiskLoader(Loader):
     """
 
     def _load(self, ann_file):
-        data_ret = []
-        with open(ann_file, 'r', encoding='utf-8') as f:
-            for line in f:
-                line = line.strip()
-                data_ret.append(line)
-
-        return data_ret
+        return mmcv.list_from_file(ann_file)
 
 
 @LOADERS.register_module()