The utility model discloses a parallel type generator circuit breaker. The parallel type generator circuit breaker includes a current-carrying loop and a cut-off loop which is connected in parallel with the current-carrying loop; when a short-circuiting fault occurs, the current-carrying loop acts rapidly, so that an arcing fracture can be formed; the arc voltage of the fracture is utilized to transfer fault current to the cut-off loop; and the cut-off loop directly cuts off the fault current or fast performs current limiting on the fault current and cuts off the fault current. According to the parallel type generator circuit breaker of the utility model, the current-carrying loop includes a load switch unit with dozens of micro ohm conduction impedance, so that it can be ensured that more than 90% of the rated current of a system can pass through the unit, and therefore, the heat loss of the generator circuit breaker GCB device can be decreased under rated condition; and at the same time, the current-carrying loop has a quick-acting ability, and generally, the current-carrying loop can be selectively cut off thoroughly in two power frequency cyclic waves after a fault occurs; the current-carrying loop can have high arcing voltage after a contact is switched off, so that rapid transfer of the fault current can be urged.