The invention discloses a dedicated main-auxiliary circuit breaker for a test station, and the circuit breaker consists of three independent circuit breakers: the A-phase circuit breaker, the B-phase circuit breaker, and the C-phase circuit breaker. Each circuit breaker comprises an a-phase main conduction loop, a b-phase main conduction loop, a c-phase main conduction loop, two control loops, and two operating mechanisms. The a-phase main conduction loops and the b-phase main conduction loops are in parallel connection, wherein one control loop is used for controlling one operating mechanism to operate. The c-phase main conduction loops are independently controlled by the other one control loop to operate through the other operating mechanism. The circuit breaker comprises three independent circuit breakers, and each independent circuit breaker comprises one a-phase main conduction loop, one b-phase main conduction loop and one c-phase main conduction loop, wherein the three main conduction loops are switched on at the same time, and the c-phase main conduction loop is switched off later than the a-phase main conduction loop and the b-phase main conduction loop, thereby improving the capability of the circuit breaker for bearing a rated current and open-circuit and circuit-break currents. Moreover, because of the delayed switch-off of the c-phase main loops and the absorption of the remaining heat of the whole generation loop through a series resistor, the whole circuit is protected.