In this study,the optimum fermentation strain was selected from four strains with excellent ability of fermenting soybean meal (Bacillus subtilis,Saccharomyces cerevisiae,Rhizopus oryzae,Penicillium chrysogenum),and crude protein content and soybean peptide content were taken as evaluation criteria to optimize the fermentation process conditions. The nutrient content and the changes of antinutrition factors were analyzed before and after solidstate fermentation of soybean meal. The results showed that B. subtilis B8 and R. oryzae M1 were the optimal combination of fermented strains. The optimum fermentation process conditions of compound fermentation were:B. subtilis and R. oryzae were simultaneously introduced into soybean meal,the inoculation ratio of two strains was 2∶1,the total inoculum of fermentation was 10%,the fermentation temperature was 40℃,the ratio of feed to water was 1.0∶1.4,and the fermentation time was 96 hours. After compound fermentation of soybean meal,the content of soybean peptide,crude protein,crude ash and crude fat in the fermentation product was significantly higher than that before fermentation (P＜0.05)，the moisture content decreased significantly (P＜0.05),the macromolecular protein was basically degraded below 10 ku,and glycinin,βconglycinin and trypsin inhibitor was significantly lower than that of unfermented soybean meal (P＜0.05). The above results indicated that the nutrient composition of soybean meal increased significantly and the antinutritional factors decreased significantly after the compound fermentation，which means that the nutritional quality of soybean meal was improved a lot.