Abstract: In order to apply the biocontrol strain HN6 to the control of banana wilt disease in the field， in the report， the preparation method of wettable powder of HN6 was explored. The single factor and multi-factor test methods were used to screen the additives of Streptomyces aureofaciens HN6 wettable powder. The results indicated that that the wettable powder with 20% fermentation product of S. aureofaciens HN6 as active ingredient， 68% diatomite as filler， 5% sodium dodecyl sulfate as wetting agent， 5% NNO as dispersant， and 2% potassium dihydrogen phosphate as stabilizer has the ideal control effects. The wettable powder under this formula has a good control effect on banana wilt disease in pot and field， and the control rates are 80.19% and 72.34% respectively， which are significantly higher than that of the control pesticide. The wettable powder of S. aureofaciens HN6 has good value in future development and application.