diff --git a/jikimo_purchase_tier_validation/models/models.py b/jikimo_purchase_tier_validation/models/models.py
index 018766eb..4462e962 100644
--- a/jikimo_purchase_tier_validation/models/models.py
+++ b/jikimo_purchase_tier_validation/models/models.py
@@ -9,6 +9,8 @@ class jikimo_purchase_tier_validation(models.Model):
     _name = 'purchase.order'
     _inherit = ['purchase.order', 'tier.validation']
     _description = "采购订单"
+    _state_from = ["draft", "to approve", "rejected"]
+    _state_to = ["approved"]
 
     _tier_validation_buttons_xpath = "/form/header/button[@id='draft_confirm'][1]"
 
@@ -68,11 +70,6 @@ class jikimo_purchase_tier_validation(models.Model):
 
         return res
 
-    def _rejected_tier(self, tiers=False):
-        res = super(jikimo_purchase_tier_validation, self)._rejected_tier(tiers)
-        self.state = 'draft'
-        return res
-
     @api.model
     def _get_under_validation_exceptions(self):
         res = super(jikimo_purchase_tier_validation, self)._get_under_validation_exceptions()