Abstract: The non-isolated grid-connected inverter is widely used because of its simple structure, small size, light weight and other advantages. However, the leakage current generated by its common mode circuit acting on both ends of the parasitic capacitance to the ground seriously affects the output power quality of the photovoltaic grid-connected system, and even endangers personal safety. In order to effectively suppress the leakage current of photovoltaic inverter clusters and improve the output power quality, this paper proposes a centralized suppression strategy for leakage current of multiple photovoltaic inverters based on carrier phase-shift control. Firstly, the carrier phase of each photovoltaic inverter is initialized according to the number of photovoltaic inverters in the system. Secondly, the central controller uses simulated annealing algorithm to optimize and compensate the carrier phase in real time based on the collected leakage current information, and sends the carrier phase compensation command to the local control unit of each photovoltaic inverter to achieve centralized suppression of leakage current of the photovoltaic inverters. Finally, the effectiveness and correctness of the proposed strategy were verified through simulation.