Abstract:With Grape skin as the raw material，this paper used the mixed fermentation of yeast and Lactobacillus plantarum to prepare the grape skin enzyme，and studied its fermentation process. Besides，this paper studied the effect of mixed strain inoculation amount，white sugar addition amount，fermentation temperature，and fermentation time on the activity of superoxide dismutase（SOD） in the grape skin enzyme through single factor experiment，determined the optimal fermentation process conditions of grape skin enzyme preparation through orthogonal test，and compared the changes of total phenolic content，total flavonoid content，and antioxidant activity of grape skin enzyme before and after fermentation. The results showed that the optimal fermentation process conditions were 0.6% mixed strains inoculated amount，12% sugar addition amount，fermentation temperature of 35 ℃，and fermentation time of 36 h. Under this condition，the SOD activity in the prepared enzyme was （62.34±0.67） U/mL，and the total phenolic and flavonoids contents were （205.62±5.18） mg GAE/100 mL and （96.47±1.21） mg Rutin/100 mL respectively. Furthermore，compared with unfermented conditions，the DPPH radical scavenging rate and ABTS+ radical scavenging rate were significantly increased by grape skin enzyme.