Breaker locking method and locking system

The invention discloses a circuit breaker locking method and a locking system. The locking method comprises the following steps: a master station terminal obtains at least one work order; the work order at least comprises a work order serial number and circuit breaker information of a circuit breaker needing to be powered off in a work task corresponding to the work order; the master station terminal sets the first state number of all circuit breakers under each work order as a work order serial number; the circuit breaker microcomputer obtains a first state number of the corresponding circuit breaker sent by the master station terminal and stores the first state number; when the circuit breaker is in the opening state, the second state number of the circuit breaker is set as the value of the first state number; the handheld terminal obtains a work order sent by the master station terminal; the work order serial number of the selected work order is continuously sent outwards according to the selection instruc