Embodiments of this application propose a low-voltage redundant power supply system, including: a high-voltage battery pack, configured to provide a first voltage and including a number of power supply units sequentially connected in series, each of the power supply units being at least one battery in the high-voltage battery pack or an equivalent power supply formed by connecting a number of batteries in series/parallel; and a relay array, with relays in the relay array connected to the power supply units in the high-voltage battery pack based on a specified connection relationship, where in at least one on/off state combination of the relay array, at least one power supply unit in the high-voltage battery pack is reused in a time-division manner to provide a second voltage to supply power to a low-voltage load; and the first voltage is higher than the second voltage.