Abstract: A power supply system and a solar photovoltaic inverter, a DC/DC module and a rectification module. Since a power supply outputted from a solar panel is low-voltage power, the power supply at an output end of the solar panel can be directly supplied to a DC driving module and a DC side circuit. Since a power supply outputted from a main transformer is high-voltage power, the AC outputted from the main transformer can be directly supplied to an inverter driving module, a rectification driving module, and an AC side circuit, without additionally providing an auxiliary power supply for high-voltage isolation, namely, without additionally providing a switching circuit, a transformer, a second rectifier module, and a third rectifier module, thereby avoiding the noise and power consumption caused by frequent ON or OFF of the switching circuit, and reducing the cost.