In order to study the stability of rock slope in a restoration project. Hoek-Brown strength criterion and equivalent M-C strength criterion were used to analyze the safety and stability of a rock slope in a restoration project by means of limit equilibrium analysis method and FLAC^3D strength reduction method. The results show that the rock slopes are stable in the process of slope cutting, and the disturbance coefficient D of rock mass is modified to compare the slope stability under different disturbance coefficients D. By comparing the results of various calculation methods, it can be seen that the slope safety factor calculated by the Hoek-Brown strength criterion is smaller than that calculated by the equivalent M-C strength criterion, indicating that the Hoek-Brown strength criterion is conservative and the equivalent M-C strength criterion will overestimate the safety of the slope. It is suggested that multiple calculation methods should be used in practical projects. The optimum calculation method is determined comprehensively. The research results can provide scientific basis for similar research.