VEHICLE-MOUNTED POWER SUPPLY APPARATUS AND VEHICLE

This application provides a vehicle-mounted power supply apparatus and a vehicle. The vehicle-mounted power supply apparatus includes a power conversion circuit, an upper-layer PCB board, a lower-layer PCB board, a bottom cover, and a radiator. The upper-layer PCB board and the lower-layer PCB board are configured to bear a plurality of power switching transistors of the power conversion circuit, so that the power conversion circuit is distributed more flexibly. The lower-layer PCB board and a plurality of transformers are fastened to a bottom plate of the bottom cover, and cooled by heat dissipation through a lower-layer cooling channel in the bottom cover. The upper-layer PCB board and the radiator are sequentially stacked above the lower-layer PCB board and the plurality of transformers, and cooled by heat dissipation through an upper-layer cooling channel in the radiator. The upper-layer cooling channel and the lower-layer cooling channel in the bottom cover communicate with each other through a side wall of the bottom cover. This improves a heat dissipation effect and temperature uniformity of the vehicle-mounted power supply apparatus.