Abstract: Abstract: Based on the analysis of the physical characteristics of the drilling seam、the technical difficulties of the drilling fluid and its adaptability requirements in the Binchang mining area, the rationality of the drilling fluid distribution in different wells is studied. The results show that in the first spud drilling, the high density and high viscosity pre-hydration bentonite drilling fluid system has good adaptability and good drilling effect. The drilling fluid density is 1.02 ~ 1.10g / cm3, the viscosity is 17 ~ 25S, the sand content is less than 4%; The second section drilling, non-target coal seam section should adopt low solid or solid polymer drilling fluid system, drilling fluid density of 1.01 ~ 1.06g / cm3, viscosity 16 ~ 20S, sand content of less than 2%;.For the target coal seam section, pointed out that the drilling fluid density window suitable for different fields, and it is appropriate to use low solid or solid-free water-based polymer drilling fluid system, also water drilling can be used, and provide reference for non-solid polymer drilling fluid formula. The paper provides the reference value for the drilling optimization of CBM development in Bingchang mining area in the future.