The invention discloses a system for testing mechanical properties of an integral circuit breaker, which comprises a host computer and an interface board is arranged on the host computer, wherein the interface board is provided with a testing line, an AC-DC terminal, a speed testing terminal, a vibration testing terminal, a direct current voltage testing terminal, an alternating current voltage testing terminal, an A-phase fracture, a B-phase fracture, a C-phase fracture and a common port terminal, wherein the interface board is connected with a sensor through the testing line. The sensor is provided with a bracket and a magnetic base. The system has abundant program control functions, wherein the sensor includes the triggering mode, the channel selection, the triggering level, and a sampling time base, a recording parameter block and the like which can be set through program control, and also includes incomparable abundant triggering functions. The system provides an ideal and effective testing tool for carrying out the overhaul of the state of a high-voltage circuit breaker for an electric power system, can be used for testing the mechanical properties of the circuit breaker on line, and performs data storage, analysis and comparison so as to quickly and accurately diagnose the health condition of the circuit breaker on line.