Abstract: The objective of this paper was to optimize the fermentation process of lactobacillus plantarum and lactobacillus casei with enzymatic hydrolysate of buckwheat,oat and pleurotus eryngii as raw material and compare the antioxidant capacity in vitro before and after fermentation. On the basis of single factor experiment,response surface methodology was used to study the effects of inoculation quantity,inoculation proportion and fermatation time on viable count in fermentation medium,and then the reducing power,scavenging ability of DPPH free radical,hydroxyl radical and superoxide anion,and total antioxidant capacity were analyzed before and after fermentation.The results showed that the best fermentation process was 4% inoculation quantity,1:1 inoculation proportion and 10.8 h fermentation time. Under the conditions,viable count was 8.89 lg(cfu/mL). And antioxidant activity has improved after fermentation. Absorbance value of reducing power,scavenging capacity of DPPH free radical,hydroxyl free radical and superoxide anion and total antioxidant capacity have increased 0.51,6.85%,43.19%,5.36%,18.29 U/mL.Through the fermentation of enzymolysis liquid of buckwheat,oats and pleurotus eryngii,its nutrition value and healthy function were better.