Abstract: The research of the formation mechanism of Huangtupo landslide complex body is very important to analyze the landslide. The original rock structure model of Huangtupo slope was built by strata correlation considering the development of weak intercalations. Weak intercalated layers developed intensively in T₂b^3-2 rock mass of slope front corresponded to the deep multistage sliding zone in Huangtupo landslide. Simulation results show there are obvious shear stress and shear strain concentration in T₂b^3-2 rock mass of slope front in the slope evolution, and the deformation influence depth can correspond to the thickness of No.1 part slide of Huangtupo landslide. The formation of No.1 part slide of Huangtupo landslide was controlled by rock mass structure of slope and its stress and strain characteristics during the slope evolution. The shear deformation of the landslide body would intensify because of the impounding of Three Gorges Reservoir. The muddy intercalations make the deep-seated landslide more easily slide.