The present invention discloses a low-power startup method and a user equipment. The method includes: running, by a user equipment UE, a first subprogram in a boot load program bootloader, so as to determine whether the UE is charged through a universal serial bus interface USB; if the UE is charged through the USB and battery power is lower than a starting threshold, initializing, by the UE, the USB; when the USB successfully enumerates the UE, running, by the UE, a second subprogram in the bootloader to initialize an off-chip random memory in the UE; running, by the UE, a third subprogram in the bootloader to read a system mirror from an off-chip flash memory in the UE and load the system mirror to the off-chip random memory; and running, by the UE, the system mirror to complete a startup.