Based on the analysis of energy consumption theory

the different reduction coefficients of strength on the cohesion and internal friction angle are assumed; different ways to define the comprehensive slope safety factor is used

and the objective function expression of respective comprehensive safety factor is derived from the principle of virtual work. Using sequential quadratic programming method and interior point method

a nonlinear programming iteration procedure for optimization solution of comprehensive safety factor is established. According to the obtained solution

we investigate the effect of double strength reduction technique evaluation method on the calculation of slope safety factor. The results show that due to many factors affecting the stability of slope

the well-determined function relationship between reduction factor of shear strength parameter c and φ does not exist; the current presupposed processing method that the strength reduction of cohesive force and internal friction angle are under a certain proportion is difficult to give full reasonable explanation. Through the shortest path of strength reduction to define the comprehensive safety factor of the slope is of more clear physical meaning

through which it can deepen engineering technicians’ understanding of strength reduction technology used in slope stability analysis.