The invention discloses a DC circuit breaker control method and device. After a first circuit model receives a trip instruction sent by a flexible DC control protection system, the first circuit module determines an instruction type of the trip instruction, and when the instruction is of a protection control type, the first circuit module generates a rapid trig signal and sends the rapid trig signal to a second circuit module; when the instruction is of a manual control type, the first circuit module generates a slow trig signal and sends the slow trip signal to the second circuit module; whenthe second circuit module receives the rapid trip signal, the second circuit module controls a DC circuit breaker to carry out rapid trip through a valve control unit; and when the second circuit module receives the slow trip signal, the second circuit module controls the DC circuit breaker to carry out slow trip through the valve control unit, so that the DC circuit breaker can carry out slow orrapid trip according to corresponding conditions. Under the condition that rapid trigger does not need to be carried out, the method and device can realize slow trip, thereby improving the disconnection success rate of the DC circuit breaker.