Abstract: According to strata control theory and different positions of key strata, we propose determination method for reasonable working resistance of hydraulic support based on key strata theory. Surrounding types is divided into four types, the easy collapse roof, the medium hardness masonry roof beam structure, the cantilever hard roof, the caving coal, according to different breaking forms of key strata. The corresponding calculation formula for various types of hydraulic support was researched to explain the reason that current domestic popular bulk mining height 4 to 8 times method was low or high sometimes in working resistance determination. Its applicability in various types of research are given, and conclusion was proved successfully.