Abstract: This paper presents a non-isolated three-port switching boost converter and applies it to photovoltaic power generation systems.The topology integrates the characteristics of the switching boost network.By controlling three switch tubes,the ports have boost,buck,and buck-boost characteristics,and have the advantages of simple structure,small size,and low cost.The working state of the system under different working modes is analyzed to realize the power flow management of the system.The control strategy is described to complete the smooth switching between different working modes.Finally,the correctness of the above theory and its application in the photovoltaic system are verified by simulation and experiment.