The control of photovoltaic grid-connected inverter introduced self-adaptive tuning of fuzzy PID control in this paper, via measured the parameter of object under controls, used fuzzy consequence, comes true to parametric PID real time adjustment¿achieved best control effect. By simulated demonstration of Matlab/Simulink, self-adaptive tuning of fuzzy PID controlling having improved the PV Grid-connected inverter system stability, has improved the mass of exporting wave, has made system be the fine moving, static state function concurrently.