The importance of renewable energy to solve greenhouse radiation has been upgraded. Photovoltaic cell is an important renewable energy. Grid-connected photovoltaic power generation system is one of the most important photovoltaic applications. The key technologies of system power conversion interface include high efficiency power converter, maximum power point tracking (MPPT) and islanding detection. In this paper, a new grid-connected photovoltaic power generation system, a new MPPT and an islanding detection mode with a new power converter control strategy are proposed. A 5 KW prototype has been developed. After testing, it conforms to the characteristics of the proposed grid-connected photovoltaic power generation system. The experimental results show that the maximum efficiency is 96. 1%, MPPT can effectively track the change of solar energy, and islanding detection conforms to the standard of UL 174 1.