The application of traditional grid inverter system,Limitations of the output voltage and current, high harmonic content and other shortcomings. Made the traditional three-phase PWM inverter and grid equivalent combination of Z-source network. Established the mathematical model of a three-phase grid-Z-source inverter.and LCL filter used for high-order harmonic filtering. LCL filters at low switching frequency and inductor are small compared to single-inductor filters has obvious advantages . Research using grid current and capacitance-voltage dual loop control strategy for grid-connected inverter control, giving the network side current control strategy component, as well as the constraints of the outer ring voltage setting. Simulation results confirm the validity of the theoretical analysis and control strategy.