Abstract: In view of the problems in the study of the strength reduction method based on double reduction parameters, the problems of double parameters strength reduction based on the analysis of the traditional strength reduction principle are summarized. By discussing the essence of strength reduction, three problems of reduction path, comprehensive safety factor and calculation result verification in the study of double parameters strength reduction are analyzed. The results show that for the strength reduction method based on strength reserve, the essence of strength reduction is to reduce the shear strength τ_f. The choice of reduction path in double parameters strength reduction is not universally applicable, and the original shear strength parameters of the slope are changed. The determination of the comprehensive stability coefficient lacks theoretical evidence, this coefficient has no definite physical meaning, and its result is not suitable for the inhomogeneous slope. The calculation of double parameters strength reduction deviates from the essence of slope stability analysis and makes the results of numerical calculation distorted.