The invention discloses a power distribution automation protecting method achieved by matching of a master station and distributed terminals. When single failure happens to a power distribution network, a failure area is determined by a power distribution automation terminal, a circuit breaker at the line outgoing position of the power distribution network is controlled to be disconnected, afterwards, section switches at the two ends of the failure area are disconnected by the power distribution automation terminal, so that failure isolation is carried out, at last, the power distribution automation terminal controls the circuit breaker at the line outgoing position of the power distribution network, an interconnection switch and the section switches to be closed, the load in a failure-free area of the power distribution network is supplied in a turning mode, and thus power restoration of the failure-free area is achieved. The power distribution automation protecting method is high in power distribution reliability, short in failure recovery time, small in power outage range and low in transformation, operation and maintenance cost, improves the distribution network planning level, lowers power grid line loss, improves the distribution network dispatching management level and improves first-aid repair working efficiency.