A three-dimensional slope stability analysis method based on finite element elastic-plastic stress field and limit equilibrium state is proposed—the three-dimensional finite element limit equilibrium method. First, calculate the unique global main sliding direction of the sliding body based on the finite element stress field, and then calculate the sliding direction of each point on the sliding surface according to the rigid body limit equilibrium assumption. The local safety factor is defined as the ratio of the shear strength to the shear stress projection in the sliding direction Finally, based on the global limit equilibrium condition of the three-dimensional slope, the local safety factor is transformed into the global safety factor by the integral mean value theorem. The method is simple to calculate, has no limitation on the shape of the sliding surface, and is reasonable and effective. The verification results of examples show that the safety factor of this method is consistent with the results of the three-dimensional rigorous limit equilibrium method, and it is suitable for sliding surfaces of arbitrary shapes.