The embodiment of the invention discloses a power failure protection method and system. The system comprises at least one transformer, a digital control terminal, a circuit breaker and a self-lockingdevice installed in low-voltage distribution equipment, wherein the digital control terminal receives electrical signals in operation of the low-voltage distribution equipment acquired by the at leastone transformer, the electrical signals are processed and analyzed, and when an opening condition is judged to be met, opening electric signals are sent to the circuit breaker to make the circuit breaker to be opened; when the digital control terminal judges to meet a reclosing condition, closing electric signals are sent to the circuit breaker to enable the circuit breaker to be reclosed; and after the circuit breaker is reclosed, when the digital control terminal judges to meet a self-locking condition, self-locking electric signals are sent to the self-locking device to enable the circuitbreaker to be opened and an opening operation is locked. Thus, intelligent power failure protection can be realized, and input on a low-voltage distribution system is also saved.