Moving contact device of circuit breaker

The invention relates to a moving contact device of a circuit breaker, comprising a hippocampus type moving contact piece, a movable contact spring and a grooved contact support in the contact deviceof the circuit breaker, wherein two bosses of protruding column-shaped structure with the size in which the moving contact spring may be hollowly sleeved and inserted exactly are fixedly connected onthe lower end surface corresponding to the upper end surface of the contact silver spot of the curved moving contact welded on the hippocampus type moving contact piece. The moving contact piece in the moving contact device provided by the invention adopts bosses of protruding column-shaped structure to firmly fix the position of the moving contact spring, so that the moving contact spring maintains the correct position in the process of closing the circuit breaker, and the service life of the circuit breaker is increased. The invention is simple in structure, easy to open molds and process, suitable for batch producti