the leakage current is harm to device or human. Based on the 3 kw photovoltaic (pv) grid inverter project as the research object, the leakage current problems, through the model building, including starting instantaneous leakage current and leakage current operation process analysis, find the inverter cause of the leakage current and leakage current solution is put forward. Through the experimental simulation analysis, effectively inhibit the 3 kw photovoltaic (pv) grid inverter system leakage current, achieve the production requirements.