Abstract: This paper mainly analyzes the abnormal defects of a VD4 circuit breaker rectifier device, through the comprehensive inspection and analysis of the field circuit breaker control loop, finally concluded that because the circuit breaker control loop in the switching-closing coil rectifier device is abnormal, the setting of this rectifier device is convenient for users to use, whether the user uses AC or direct current. Circuit breakers can operate normally, while most of the power grid uses direct current to control the switching of circuit breakers. The rectifier device itself is easy to be damaged, which directly leads to the circuit breaker refusing to operate after damage, and there are hidden dangers in the operation of the power grid. At the end of the paper, it is proposed that the incoming line "+", "-" (L and N) are short-connected with the coil end "+" and "-" respectively to bypass the rectifier bridge. The direct input of direct current into the switching coil can effectively avoid the treatment method of the meaningless rectifier bridge frequent damage resulting in switch rejection, so as to improve the power supply reliability of the power system.