Abstract: In this paper,the antifungal activities of different lactic acid bacteria were investigated by primary screening and secondary screening,and wheat germ oil was added to the culture medium of lactic acid bacteria for fermentation,in order to clarify the effect of lactic acid bacteria and wheat germ oil fermentation on the antifungal activity of Aspergillus niger. The results showed that wheat germ oil did not have the ability to inhibit the growth of Aspergillus niger,but the inhibition rate of LF5 fermentation liquid significantly increased with the increase of wheat germ oil concentration,and the phenomenon was strain specific. By heating,neutralizing pH,adding protease and catalase,it was found that the antifungal active substances in the supernatant of Lactobacillus cooperative fermentation were mainly composed of organic acids and some non protein components with good thermal stability. In addition,Lactobacillus fermentans LF5 was used to prepare bread with wheat germ oil fermentation. On the 5th day,mold was found to be visible to the naked eye,which significantly inhibited the growth activity of Aspergillus niger compared with the blank group,providing a new direction for the application of Lactobacillus in fermented food.