In order to analyze the influence of the rotation of the maximum principal stress direction of the roof on the deformation and damage of the roof, taking the 25221 working face of 2130 mine of Xinjiang Coking Coal Group as the background, the roof failure and the evolution characteristics of the rock structure are analyzed by the physical similarity simulation experiment and FLAC3D numerical simulation method, the maximum principal stress direction deflection and its impact on the roof damage. On this basis, the roof mechanical model is established to discuss the distribution characteristics of the roof deflection. With the advancement of coal mining, the range of bearing arch above the roof failure envelope increases, and the arch extends to the middle and upper part of the rock stratum; The contour distribution pattern of the maximum principal stress direction of the roof gradually evolves from "m" to "n" type (The maximum principal stress direction of the roof in the middle and upper part of the goaf deflects greatly). Under the synergetic effect of the principal stress direction deflection and the optimal expansion crack angle, the middle and upper parts of the roof are damaged and migrate to the high level rock stratum, gradually; Establish the roof mechanical model, and substitute the roof data into the calculation through Python programming, so that the deflection peak value, along the tendency, will appear at 4/5 of the roof.