Low-voltage power supply system of new energy vehicle and control method of low-voltage power supply system

The invention discloses a low-voltage power supply system of a new energy vehicle. The new energy vehicle is equipped with a battery pack which is taken as power energy, wherein the two electrodes ofthe battery pack are connected to a battery management system; the battery management system is equipped with a slow charging interface connected to a charging machine and a quick charging interface connected to direct-current quick charging equipment; the two electrodes of the battery pack are connected to the input end of DCDC, and the low-voltage output end of the DCDC is connected to a vehicle-mounted power consumption apparatus; a DCDC fuse and a DCDC relay are connected between the positive electrode of the battery pack and the DCDC in series; and a relay control interface of the batterymanagement system is connected to an input end loop of the DCDC relay. The system solves low-voltage power supply, reduces whole vehicle cost, and prevents the battery over-discharge problem due to too low battery pack electr