The invention relates to a region protection differential ring boundary circuit breaker dynamic search method. The method comprises the following steps: 1) for one regional network, analyzing an SCD file of a substation therein, and extracting equipment structure data information of each substation; and 2) selecting a primary part requesting for protection configuration, for each line, finding all circuit breakers, the on-off states of which are off, on nodes directly connected with the two ends of the line, the circuit breakers being basic differential rings of the line; and for a bus, finding circuit breakers, the on-off states of which are off, connected with a bus node, and circuit breakers, the on-off states of which are off, on nodes connected with the bus node through the line, the circuit breakers being basic differential rings of the bus. Through combination of substation configuration description language SCL and real-time on-off state of the circuit breakers, a differential ring boundary circuit breaker of a protected device is searched, and the differential ring boundary circuit breaker is adjusted dynamically through self-checking of the on-off state of the circuit breakers; and the method is high in accuracy and simple in search process.