The invention provides a scanning unit, and an output control method of a redundant trigger. The scanning unit comprises a plurality of triggers, a selection module and a voting machine; triggering signal input terminals of the plurality of triggers are connected; clock signal input terminals of the plurality of triggers are connected; an input terminal of the selection module is separately connected with an output terminal and a selection signal input terminal of each trigger; the selection module is used for outputting an output signal of the corresponding trigger according to a selection signal; the voting machine is separately connected with a first trigger of the plurality of triggers and two output terminals of the selection module; and the voting machine is used for performing voting according to an output signal of the first trigger and the output signal of the selection module and outputting a fault-tolerance signal or outputting a verification signal to verify whether the trigger has a fault. According to embodiments of the scanning unit and the method, the scanning unit has good fault-tolerance capability, the circuit reliability is improved, the test time is greatly reduced, the diagnosis speed of scanning chains is accelerated, and the positioning accuracy is improved.