The invention belongs to the field of control over electric systems, and particularly relates to a distributed power failure protection device and method suitable for a multi-source power grid. The device comprises a central monitoring unit, an A-phase distributed power failure protection unit, a B-phase distributed power failure protection unit, a C-phase distributed power failure protection unit and a converter. According to the device and method, the failure current increasing rate at the moment of the failure current and the short-circuit current amplitude in the fault ride-through period are limited by means of the inductance of a failure protection circuit, and the impact of the failure current on a device is reduced in both the normal operation state and the system failure state; low voltage ride through is ensured by means of shunt energy dissipation resistance and current-limiting inductance in the failure period on the premise that the original operating state of a distributed power supply is unchanged; switching response delay of the protection device is avoided, the instantaneous peak value of the failure current and the short-circuit current amplitude in the fault ride-through period can be restrained effectively in time, and damage to a source-end device caused by the instantaneous peak value of the failure current and the short-circuit current amplitude in the fault ride-through period is avoided.