Abstract: To provide theoretical basis and technical parameters for the experimental study of a functional milk with auxiliary blood pressure,in this study,the medicine-food homologous Chinese herbal medicine with blood pressure lowering effect and milk proteolytic solution with blood pressure lowering activity were compounded. The experiment is to optimize the optimal process of trypsin enzymatically skimmed milk with ACE inhibition rate as an indicator.The extracts with high ACE inhibitory activity were screened from 15 kinds of Chinese herbal medicines.Formula of high ACE inhibitory activity were obtained by mixed milk protein hydrolysate and the selected Chinese herbal extracts. The best reaction conditions were as follows:The substrate concentration 7 g/100 mL,enzymolysis time 6 h,the amount of enzyme 5%,enzymatic hydrolysis temperature 31℃,pH6.9,under the experimental conditions,defatted milk solution ACE inhibition rate was 58.51%. Hawthorn and Cassia seed have higher ACE inhibition rates,which are 50.88% and 45.34%,respectively.When Hawthorn and cassia extract were mixed,the ACE inhibitory activity was increasing. The ACE inhibitory activity was 52.52% when Hawthorn and cassia extract were mixed by 2:1. The ACE inhibitory activity was 59.09% when the enzyme solution and Chinese herbal medicine extract(Hawthorn and cassia mixed extract were mixed by 2:1)were mixed by 1:1.It has theoretical and practical significance for the study of health-care functional dairy products with the effect of regulating blood pressure.