Taking Bacillus amyloliquefaciens Z17-2,which has antagonistic effect on potato black scurf,as a test organism.The medium and culture conditions were optimized by single factor and orthogonal test.The results showed that the optimal medium composition was as follows:maltose 20 g/L,soybean meal 10 g/L,NaCl 1 g/L,CaCl₂1 g/L,MgSO₄·7H₂O 1 g/L.The optimal culture conditions were as follows:inoculation amount of 2%,liquid loading amount of 50 mL/250 mL,initial pH 6.0,temperature of 35℃,shaking speed of 220 r/min.Under the optimal culture conditions,Z17-2 reached the stable stage after 30 h culture,and the OD value of fermentation broth reached 1.591,which was 120% higher than that before optimization,and the antibacterial activity increased by 43.8%.