Abstract: One of the core problems faced by a large number of slope support projects in Northwest China is the stability analysis of multi-stage high slopes. However, most of the existing stability analysis methods are for the sigle-stage high slopes. Based on the Swedish slice method, a method for stability calculation of multi-stage high loess slopes and the relevant sliding surface search model are proposed. The stability algorithm is analyzed by means of the MATLAB software programming and thefinite element simulation. The results show that: (1) The proposed method and the relevant sliding surface search model can be used to evaluate the overall stability of the multi-stage slopes and modified according to the sensitivity analysis. (2) According to the sensitivity analysis, the slope height and the slope ratio are the primary factors to be considered in the design of its grade. At the same time, with the decrease of the gravity, the increase of the cohesion and the increase of the friction angle, the slope stability will be improved. (3) Through the finite element simulation software, it is found that the sliding surface obtained by the proposed sliding surface search model is more accurate, and the sliding surface of the slope has moved back after the support. (4) According to the support case of multi-stage loess slope, it is found that the stress of the joint between the anti-slide piles and the prestressed anchor cable of the frame and the soil in front of the anti-slide piles is high, and the axial tension of the anchor cable in the lower row is large, which should be emphasized in the design of similar projects. The above research results may provide scientific basis for the stability analysis of multi-stage high loess slopes.