The invention provides a device for testing breaking-closing interlocking force of a circuit breaker. The device comprises a fixed frame, a disc spring reset component, a transmission shaft, a first connector and a second connector, the disc spring reset component comprises a hinge seat, a disc spring, a disc spring mounting column and a fixing shaft, the hinge seat is fixedly arranged on the fixed frame, one end of the disc spring mounting column is movably connected with the hinge seat, the other end of the disc spring mounting column is sleeved on the fixing shaft and fixedly connected with the fixing shaft, the disc spring is sleeved on the fixing shaft and arranged in the disc spring mounting column, the lower end of the fixing shaft is connected with the first connector, the first connector is connected with the transmission shaft, the transmission shaft is arranged on the fixed frame, and the second connector is connected with the transmission shaft. According to the device, the device is connected with a breaker, the interlocking force can be detected, so that the interlocking force is monitored, and the requirement of the interlocking force is met.