The logistics industry is developing rapidly, and a large number of logistics sorting robots are put into use. The charging method is mainly based on contact charging, and there are certain safety hazards. Therefore, this paper proposes to use the magnetic coupling resonant wireless power transmission technology for wireless charging. The system of mutual inductance is used to model and analyze the system. The finite element software COMSOL is used to simulate the coils of the wireless power transfer system. The magnetic simulation and numerical calculation of the proposed three coil simulation models are carried out. The simulations and analysis of the three models are carried out. The effect of magnetic field strength distribution and distance variation on transmission characteristics. The simulation results show that the transmission efficiency and load power of the rectangular orbit wireless power transmission system are relatively stable, which is more suitable for wireless charging of the sorting robot.