OBJECTIVE To optimize the water extraction process of Maxing kechuan granules. METHODS With the contents of ephedrine hydrochloride， bergenin， prim-O-glucosylcimifugin， 5-O-methylvisamin， naringin and hesperidin and the rate of extraction as the evaluation indexes， the weight was determined by the analytic hierarchy process（APH）-entropy weight method， and the comprehensive score was calculated as the response value. Based on the single-factor test， the Box-Behnken response surface method was used to investigate the factors， and the best water extraction process of Maxing kechuan granules was optimized； process validation was also carried out. RESULTS The best water extraction process of Maxing kechuan granules optimized was as follows： soaking for 40 minutes， adding 8 times water， and extracting for 180 minutes. After three validation tests， the comprehensive score was 94.82 （RSD＝0.96%， n＝3）， which had a small difference from the predicted value of 94.64. CONCLUSIONS The water extraction process of Maxing kechuan granules is stable and reliable， which can provide a reference for the development of the preparation.