Abstract: A backup-type power supply system aims to integrate power output according to different potentials through different power supply modules. Each power supply module includes backup-type N+1 power supply devices and an independent power balance unit to output power in a balanced fashion so that users can add the power supply module of independent potential according requirements. Thereby transformation power loss of the power supply devices can be reduced. The power supply devices can be designed with different specifications and dimensions corresponding to different electronic devices.