Abstract: The working face of Wangjialing coal mine adopts the layout of “double entry and primary return”, in which the auxiliary transport roadway of the upper working face is reused as the return air groove of the next working face, which is the roadway with strong dynamic pressure of supporting top coal, and the roadway maintenance is difficult.Therefore, it is necessary to research on its deformation mechanism and propose the corresponding reinforcement design.Through the analysis of the roof separation of the dynamic pressure roadway, the deformation monitoring of roof and two sides, the force monitoring of supporting members, combined with the peeping of roof strata, the deformation characteristics of dynamic pressure roadway with top coal in Wangjialing coal mine are mastered, the roof separation main occurs in the top coal.Numerical simulation is used to analyze the deformation mechanism of roof in caving roadway under dynamic pressure, affecting factors including top-coal thickness, dynamic pressure influence degree, different supporting design, think the top-coal thickness and top-coal supporting situation directly decided to top-coal deformation condition, the roadway support design should fully consider the roof support top strength and stiffness.According to the deformation characteristics and deformation mechanism, combined with the high prestressed bolt supporting technology, the dynamic pressure roadway reinforcement design is put forward and the underground practice shows that the reinforcement effect is good.