In order to optimize the AGV charging mode, a wireless power transmission system was designed for wireless charging of outdoor large-load AGV trolleys. The wireless power transmission system included three modules: AC/DC power module, high-frequency inverter module and receiver rectifier module. In the AC/DC power module, Huawei R95021G1 power module was adopted, and the output low-voltage mode could achieve 10 kW output under normal system topology parameters, the output high-voltage mode could realize high-voltage and low-current output state.By the high-frequency inverter module, the DC input was converted into high-frequency AC output, and the output was wired to the ground-side coil topology;by the receiving-end rectifier module, the AC voltage of the receiving coil was rectified to DC output to supply DC loads or charge battery loads. It communicated with the inverter power supply through WiFi to realize the closed-loop adjustment of output parameters and report the implementation status. In this design, the magnetic coupling full-bridge S-S wireless power transmission technology was selected, and the frequency tracking algorithm was used to adjust the PWM duty cycle and the output voltage of the PFC module in real time to control the charging power. Finally the wireless fast charging of the AGV is realized, with accurate positioning and non-contact sparks. The system runs stably.