The fermentation characteristics of Lactic acid bacteria strains like Leuconostoc mesenteroides, Lactobacillus plantarum and Pediococcus pentosaceus were researched respectively. According to the growth situation, acid-producing ability, salt resistance, temperature tolerance and adaptability to different pH value of strains, the Leuconostoc mesenteroides, Lactobacillus plantarum and Pediococcus pentosaceus were all could be used as mustard’s fermentation strains. In the mixed strains proportioning optimization experiment, the ferment effect of Leuconostoc mesenteroides∶Lactobacillus plantarum∶Pediococcus pentosaceus = 2∶3∶2 which was the best, the total acid content of the fermented product was 1.07%, the amino acid nitrogen content was 0.16%, the volatile ester content was 2.48 g/kg, the sensory score was 91.0, the quality was high, and it was the best starter for the inoculation and fermentation of dry mustard.