diff --git a/convlab/dst/rule/multiwoz/usr_dst.py b/convlab/dst/rule/multiwoz/usr_dst.py
index 962582b0c3b9886c7cb581efa28bd3acd8915bb3..1de65476b6f0a6a0f419d733af867717c4c1729a 100755
--- a/convlab/dst/rule/multiwoz/usr_dst.py
+++ b/convlab/dst/rule/multiwoz/usr_dst.py
@@ -6,12 +6,18 @@ from convlab.dst.rule.multiwoz.dst_util import normalize_value
 from convlab.dst.rule.multiwoz import RuleDST
 from convlab.util.multiwoz.multiwoz_slot_trans import REF_SYS_DA
 from convlab.policy.tus.multiwoz.Da2Goal import SysDa2Goal, UsrDa2Goal
-from data.unified_datasets.multiwoz21.preprocess import normalize_domain_slot_value, reverse_da
 from convlab.policy.rule.multiwoz.policy_agenda_multiwoz import unified_format, act_dict_to_flat_tuple
+import importlib
 from pprint import pprint
 from copy import deepcopy
 from convlab.util import load_ontology
 
+module_spec = importlib.util.spec_from_file_location('preprocess', \
+    os.path.abspath(os.path.join(os.path.abspath(__file__), f'../../../../../data/unified_datasets/multiwoz21/preprocess.py')))
+module = importlib.util.module_from_spec(module_spec)
+module_spec.loader.exec_module(module)
+reverse_da = module.reverse_da
+
 SLOT2SEMI = {
     "arriveby": "arriveBy",
     "leaveat": "leaveAt",
diff --git a/convlab/evaluator/multiwoz_eval.py b/convlab/evaluator/multiwoz_eval.py
index e32e2fe9f483476e1658540ff73502bce53986cc..115f39e64958da727d51ea91431bb8eaa6ef5a5d 100755
--- a/convlab/evaluator/multiwoz_eval.py
+++ b/convlab/evaluator/multiwoz_eval.py
@@ -7,7 +7,14 @@ from copy import deepcopy
 from convlab.evaluator.evaluator import Evaluator
 from convlab.policy.rule.multiwoz.policy_agenda_multiwoz import unified_format, act_dict_to_flat_tuple
 from convlab.util.multiwoz.dbquery import Database
-from data.unified_datasets.multiwoz21.preprocess import reverse_da
+import os
+import importlib
+
+module_spec = importlib.util.spec_from_file_location('preprocess', \
+    os.path.abspath(os.path.join(os.path.abspath(__file__), f'../../../data/unified_datasets/multiwoz21/preprocess.py')))
+module = importlib.util.module_from_spec(module_spec)
+module_spec.loader.exec_module(module)
+reverse_da = module.reverse_da
 
 requestable = \
     {'attraction': ['post', 'phone', 'addr', 'fee', 'area', 'type'],
diff --git a/convlab/policy/rule/multiwoz/policy_agenda_multiwoz.py b/convlab/policy/rule/multiwoz/policy_agenda_multiwoz.py
index 0919f0bd18b83120a4c572a72c05b3054a479600..432f8eb214c6384cd8cec439abfb8d4dc4ec1e7c 100755
--- a/convlab/policy/rule/multiwoz/policy_agenda_multiwoz.py
+++ b/convlab/policy/rule/multiwoz/policy_agenda_multiwoz.py
@@ -16,8 +16,14 @@ import logging
 from convlab.policy.policy import Policy
 from convlab.task.multiwoz.goal_generator import GoalGenerator
 from convlab.util.multiwoz.multiwoz_slot_trans import REF_USR_DA, REF_SYS_DA
-from data.unified_datasets.multiwoz21.preprocess import normalize_domain_slot_value, reverse_da
-
+import importlib
+
+module_spec = importlib.util.spec_from_file_location('preprocess', \
+    os.path.abspath(os.path.join(os.path.abspath(__file__), f'../../../../../data/unified_datasets/multiwoz21/preprocess.py')))
+module = importlib.util.module_from_spec(module_spec)
+module_spec.loader.exec_module(module)
+reverse_da = module.reverse_da
+normalize_domain_slot_value = module.normalize_domain_slot_value
 
 def unified_format(acts):
     new_acts = {'categorical': []}
diff --git a/convlab/policy/tus/multiwoz/TUS.py b/convlab/policy/tus/multiwoz/TUS.py
index b9f7c5cc2c769261e0a0388a818919e7f29cdf3f..0fef5f0f09a65caffdecd24214c6da9cd94c2c98 100644
--- a/convlab/policy/tus/multiwoz/TUS.py
+++ b/convlab/policy/tus/multiwoz/TUS.py
@@ -15,8 +15,15 @@ from convlab.policy.policy import Policy
 from convlab.task.multiwoz.goal_generator import GoalGenerator
 from convlab.util.multiwoz.multiwoz_slot_trans import REF_USR_DA
 from convlab.util.custom_util import model_downloader
-from data.unified_datasets.multiwoz21.preprocess import normalize_domain_slot_value, reverse_da
 from convlab.policy.rule.multiwoz.policy_agenda_multiwoz import unified_format, act_dict_to_flat_tuple
+import importlib
+
+module_spec = importlib.util.spec_from_file_location('preprocess', \
+    os.path.abspath(os.path.join(os.path.abspath(__file__), f'../../../../../data/unified_datasets/multiwoz21/preprocess.py')))
+module = importlib.util.module_from_spec(module_spec)
+module_spec.loader.exec_module(module)
+reverse_da = module.reverse_da
+normalize_domain_slot_value = module.normalize_domain_slot_value
 
 
 DEVICE = torch.device("cuda" if torch.cuda.is_available() else "cpu")
diff --git a/convlab/policy/vector/vector_base.py b/convlab/policy/vector/vector_base.py
index 72970ba1d46b293666477550ac33c5497b7c6d6a..a5d1b382262757e508f7e0e44b93543d07d846b5 100644
--- a/convlab/policy/vector/vector_base.py
+++ b/convlab/policy/vector/vector_base.py
@@ -4,7 +4,6 @@ import sys
 import numpy as np
 import logging
 
-from data.unified_datasets.multiwoz21.database import Database
 from copy import deepcopy
 from convlab.policy.vec import Vector
 from convlab.util.custom_util import flatten_acts
@@ -27,8 +26,8 @@ class VectorBase(Vector):
         self.set_seed(seed)
         self.ontology = load_ontology(dataset_name)
         try:
-            #self.db = load_database(dataset_name)
-            self.db = Database()
+            self.db = load_database(dataset_name)
+            # self.db = Database()
             self.db_domains = self.db.domains
         except Exception as e:
             self.db = None
diff --git a/convlab/util/multiwoz/lexicalize.py b/convlab/util/multiwoz/lexicalize.py
index 7afced06dd35253ea998feaca97fa3b9872f903d..4c30014dbc936978d356df40ff39a9f67c0eec0a 100755
--- a/convlab/util/multiwoz/lexicalize.py
+++ b/convlab/util/multiwoz/lexicalize.py
@@ -1,8 +1,14 @@
 from copy import deepcopy
 
 from convlab.util.multiwoz.multiwoz_slot_trans import REF_SYS_DA
-from data.unified_datasets.multiwoz21.preprocess import reverse_da_slot_name_map
+import os
+import importlib
 
+module_spec = importlib.util.spec_from_file_location('preprocess', \
+    os.path.abspath(os.path.join(os.path.abspath(__file__), f'../../../../data/unified_datasets/multiwoz21/preprocess.py')))
+module = importlib.util.module_from_spec(module_spec)
+module_spec.loader.exec_module(module)
+reverse_da_slot_name_map = module.reverse_da_slot_name_map
 
 def delexicalize_da(da, requestable):
     delexicalized_da = []