Abstract: Bacillus amyloliquefaciens B1619 was expected to develop into a biological germicide, which could effectively prevent and control facility vegetables wilt occurrence and damage. In this study, we explored the effect of auxiliaries and fillers on living bacterium quantity, compared the physicochemical properties, and determined the optimum formula: B1619 fermentation liquid 15%, binder magnesium aluminum silicate 3%, dispersant naphthalene sulfonate formaldehyde condensate 2%, disintegrating agent ammonium sulfate 5%, wetting agent lauryl sodium sulfate 1%, fillers Kaolin 24%. The properties of “Biological germicide Bacillus amyloliquefaciens B1619 with 120 million living bacterium per gram of water dispersible granules (WDG)” was measured, the results show that the content of B1619 living bacterium was more than 1.2×10⁸cfu/g, suspension percentage was 90%, wetting time was 15 s, disintegration time was 30 s, moisture content less than 5%, thermal stability was up to standard. All of the indexes of the sample were conform to the product standard.