Based on a four-legged walkable lander with a series-parallel hybrid leg-foot mechanism, the Newton-Euler method is applied to study the dynamic modeling of the joint energy consumption problem during walking in order to understand the problem of joint energy consumption during walking. Firstly, the D-H method is used to establish the joint coordinate system of the series-parallel mixed leg-foot mechanism, and the forward kinematics and inverse kinematics are derived. Secondly, on the basis of the kinematic model, the Newton-Euler method is used to establish a full-state dynamic model of the lander, which takes the relative trajectory of the foot end as the input to obtain the change curve of the force in each joint during the movement of the lander. Finally, the five-order spline interpolation method is used to plan a section of motion trajectory, and the ADAMS simulation software is used to simulate the virtual prototype of the lander. It is verified that the theoretical calculation value of the dynamic model and the numerical simulation result of the virtual prototype have the same change trend, which proves the validity of the model and can be used as the basis for the establishment and optimization of subsequent energy consumption model.