The main function of the combiner box is to conduct primary confluence on the input of the photovoltaic cell array, which is used to reduce the connection between the photovoltaic cell array and the inverter, optimize the system structure, and improve the reliability and maintainability. A certain number of photovoltaic cells with the same specifications are connected in series to form a photovoltaic tandem, and then several photovoltaic tandem are connected in parallel to the photovoltaic combiner box. After converging in the photovoltaic combiner box, the controller, DC distribution cabinet, photovoltaic inverter, and AC distribution cabinet are used together to form a complete photovoltaic power generation system and realize grid connection with the municipal power supply. The combiner box adopts a closed design, which is waterproof, dustproof and heat dissipation, and is suitable for indoor and outdoor installation.