In view of the instability and discontinuity caused by the uncertainty of new energy power generation sources, a low frequency isolated single-stage two-input grid-connected inverter for combined wind and photovoltaic (PV) power supply is proposed. In this paper, deep research is done on the control topology and circuit topology. The small signal mathematical model is established by using the state space averaging method, and the design method of the current regulator under the coupling of control variables is given. By decomposing the filtering inductor current, the quality of the grid-connected current waveform and the maximum power output of each input source are ensured by the control maximum power output SPWM strategy. Simulation results verify the effectiveness of circuit topology and its control strategy.