#$%^&*AU2020101344A420200820.pdf#####Austracy The present invention provides a Bacillus siamensis MC2-1 having a collection number of CGMCC No.15974 and a collection date of June 20, 2018. The Bacillus siamensis MC2-1 CGMCC No.15974 in the present invention has activity of producing protease, amylase and lipase, and is isolated from the digestive tract of Periplaneta americana. The strain in the present invention has the function of an obvious antagonism on Beauveria bassiana, is safe to silkworm larvae, and is a silkworm white muscardine prevention microbe having application prospects. 1