Abstract: Aiming at the shear failure of drilling casing, based on the movement law of overlying strata in coal seam mining, the finite element model of shear deformation of drilling casing is established by ANSYS numerical simulation software, and the effect of different strata dip angles on the stress distribution in the shear deformation area of drilling casing is simulated and analyzed. The results show that after shear deformation of casing, the shear plane changes from original circular to elliptical, and the end point of elliptical long axis is the stress concentration area of shear stress. Increasing the dip angle of strata will result in the increase of the stress concentration area of casing shear stress, and the maximum shear stress in the stress concentration area also gradually increases.