In order to explore a high quality and safe preservation method of pickled mustard， the effects of ozone sterilization， potassium sorbate， sodium pyrosulfite and citric acid on the preservation quality of pickled mustard were studied by orthogonal test with four factors and three levels. The results showed that the total acid content was the decisive factor affecting the total bacterial count of mustard after one week of destructive storage at 37 ℃， and the content of amino nitrogen， which reflected the degradation degree of mustard， was the limiting factor affecting the fluctuation of the total bacterial count， mainly through the inhibition of mustard degradation by sodium pyrosulfite， which had a large indirect negative effect on the total bacterial count； O3 treatment was the decision factor to promote the decrease of nitrite content. After 2 weeks of storage， potassium sorbate was the limiting factor affecting the discoloration of mustard， and it had produced a great indirect negative effect on the L value of mustard， mainly through inhibiting the pigment decomposition of mustard by bacteriostasis. There was a significant positive correlation between the yellow degree of mustard and the total number of bacteria (r = 0.858， P = 0.003) and nitrite content (r = 0.851， P = 0.004)， which could be used as an evaluation index of appearance quality. The optimal process combination was 0.8 mg/L O3 treatment for 3 min， sodium pyrosulfite content of 0.30 mg/mL， citric acid content of 1.00 mg/mL.