A circuit breaker with quick response and separation and a quick response and separation method for the circuit breaker. The circuit breaker comprises a breaking contact group (10) and a joint contact group (20). The breaking contact group comprises a movable breaking contact (11). The joint contact group comprises a movable joint contact (21). A movable contact limiting device (31) used for limiting moving positions of the breaking contact and/or the joint contact is arranged between the breaking contact group and the joint contact group. The quick response and separation method for the circuit breaker comprises a breaking and opening step, wherein the breaking contact reversely moves and is separated independently ahead of the joint contact, or the breaking contact and the joint contact reversely move and are separated at the same time. The breaking contact is adopted in the circuit breaker to replace a fixed contact in the conventional art, and when the circuit breaker needs to carry out opening and breaki