The utility model relates to an auxiliary detector for the drive circuit of a breaker, which is characterized by comprising an adjustable resistor connected in series with the coil of the breaker so as to realize the current limiting effect, and a microcontroller. The microcontroller is connected with two signal input terminals through an intermediate relay (ZJ). The micro-controller is also connected with a voice alarm. In this way, when signals are input through the two signal input terminals, switching signals are transmitted through the intermediate relay (ZJ) to the microcontroller so as to enable the voice alarm to give a voice prompt. Trials show that, when the auxiliary detector for the drive circuit of a breaker is connected in series with a control circuit, the correctness of the circuit verification result during the non-actuating time of the breaker can be ensured. Therefore, the action times of the breaker are greatly reduced and the service life of the breaker is prolonged. Meanwhile, the burn-out risk of the coil of the breaker is lowered. The auxiliary detector has the advantages of light weight, simple operation, convenient carrying, easy and flexible application, short testing time and the like.