The utility model provides a pair of electrified change instrument of direct current system insulation monitor, connection cable is with insulation monitor by place return circuit bypass, direct current voltmeters and direct current table are used for showing the magnitude of voltage and the current value in insulation monitor place return circuit, when changing insulation monitor, can be conveniently with the insulation monitor bypass, then the indicating value according to direct current voltmeters and direct current table judges whether can directly change insulation monitor, the operation of need not cutting off the power supply when changing insulation monitor, the labor intensity of operating personnel is reduced, insulation monitor changes conveniently. Closing switch is used for controlling connection cable's break -make, and the wiring of change instrument is convenient, and the combined floodgate pilot lamp is lighted after closing switch closes a floodgate to the suggestion technical staff can carry out related operations, has optimized the performance who changes the instrument. The wiring that does benefit to the change instrument that is provided with of the wiring body is operated, has reduced technical staff's intensity of labour.