In order to explore the stress deflection and stability analysis of roof under the support of gangue in large dip angle working face, the fracture evolution characteristics of gangue support area and roof rock beam under unbalanced filling effect are studied based on theoretical analysis. Combined with numerical calculation, the asymmetric space-time deformation and stress deflection response law of coal rock in stope are analyzed, and the influence mechanism of gangue on the mining dynamic behavior of surrounding rock in large dip angle stope is revealed. The research results show that : affected by the gravity inclination effect, the gangue support filling area changes with the coal seam inclination angle and coal thickness. The length of the gangue support area in the working face is 35.44 m, and the roof is prone to breakage and instability at 75 m. The unloading of coal seam mining leads to the formation of stress concentration at the upper and lower ends and the gangue filling area. The direction of the principal stress vector of the overburden rock is asymmetrically deflected. The principal stress deflection angle gradually decreases from the middle and upper regions to the two sides of the boundary. The peak value of the principal stress deflection angle is 70.05 °. The change rate of the principal stress difference and the shear stress of the rock stratum decrease with the increase of the principal stress deflection angle. The caving gangue bears part of the overburden load, and the stress transfer path changes. There are two asymmetric stress deflection boundaries in the rock layer. The advance abutment pressure of the working face decreases as a whole, and the decrease in the lower part of the tendency is the largest. The peak abutment pressure is transferred to the lower part of the non-filling area.