To improve the single-unit capacity and overall transmission capability of wireless power transmission systems. This paper proposes a multi-load wireless power transmission system based on a three-phase inverter.The transmitting end uses a voltage-type bipolar SPWM controlled bridge inverter,and the receiving end is composed of three independent units with parallel resonant circuits.Through the theoretical derivation of the coupling circuit,the system transmission efficiency formula is obtained,and the relationship between transmission efficiency and load and mutual inductance coefficient is analyzed.On this basis,an adaptive PID control scheme for constant current output of the transmission system and a load cut-in and cut-out control method are proposed.Finally,the effectiveness and feasibility of the mentioned topology and control scheme are verified through MATLAB simulation and a physical experiment platform. The output power of each phase of the three phase transmission system reaches about 60 W,and the transmission efficiencies reach more than 90%respectively,which is equivalent to the output power and transmission efficiency of a single-phase wireless system,effectively improving the singleunit capacity and transmission capability of the transmission system.