Abstract： In this paper, numerical analysis of a domestically developed leg mating unit (LMU) test model was conducted using nonlinear FEM. The characteristics of the loaddisplacement relationship and stress distribution were discussed. The stress and displacement in the measurement points were compared with the model test results. The comparison indicates that the results of nonlinear FEM agree well with the model test. As a consequence, nonlinear FEM can be applied in the design and development of LMU. The method and the conclusion can provide reference for the design and analysis of LMU.