Abstract: Taking 19 bacteria obtained from the saline-alkali soil in Dunhuang area as test materials, they were selected by the plate confrontation method and myphelium growth rate method, and were identified by the morphological characteristics, physiology and biochemical test and 16 S rDNA sequence analysis, and the antagonistic bacteria were selected by potted plant test, in order to obtain the strong antagonism of cucumber wilt pathogens.The results showed that 19 antagonist bacteria were isolated from saline-alkali soil in Dunhuang, with the inhibition rate was 79.22%.The identification of endogenous Bacillus endophyticus,showed that the fermentation liquid had significant control effect on cucumber blight.The condition index of cucumber seedlings was 28.14 and the control effect reached 69.77%.It was showed that the isolated Bacillus strain A7-3-14 can be used for biological control of cucumber blight and has good results.