Abstract: In this paper, considering the flyback grid-conneted micro-inverter, the structure and principle of the single-phase grid-conneted micro-inverter are described firstly, and the working principle of flyback converter is analyzed in detail when the active clamp circuit is joined. Secondly, the control system modeling of flyback micro-inverter is analyzed and the parameters of the main power circuitare are designed. Finally, through this prototype verify the active clamp circuit not only the voltage spikes are effeetively limited when the main switch of the flyback is turn-off and achieve the zero voltage switch (ZVS), but also does not affect the function of power generation.