The invention discloses a dual-breakpoint moving contact system of a moulded-case circuit breaker. The dual-breakpoint moving contact system comprises a spindle, a moving contact module, shafts, and springs. The spindle is cylindrical. Two through holes in central symmetry and for passage of the shafts are formed in the spindle. A through channel is formed in the spindle, and the edge of the inner wall of each end of the through channel is provided with two grooves. The moving contact module comprises a rotor, moving contact plates, the rotating shafts, spring-hanging shafts, plate springs and fastening screws. The rotor is disposed in the through channel. The springs are hung between the spring-hanging shafts. The rotor is in central symmetry. Two ends of the rotor are provided with grooves, and the side of each groove is provided with a through hole used for passage of one rotating shaft and mounting of the corresponding moving contact plates. The plate springs are mounted at one end of the rotor through the fastening screws, are located above the moving contact plates and contact with the moving contact plates. The dual-breakpoint moving contact system is provided with multiple moving contact plates, and through both increase of the moving contact plates and increase of contact bridge current-carrying area, operating current value of the dual-breakpoint moulded-case circuit breaker is increased effectively.