The utility model relates to a mounting tool for fitting bolt and ground potential nut is refered in particular to in the power maintenance field, including insulator spindle, connecting portion, nut installation head, the insulator spindle includes the mount pad, the mount pad is located the front end of insulator spindle, and the mount pad is the disc structure, is provided with the spaced teeth of a cogwheel of each other and recess on one of them planar circumferential edge of mount pad, the shape of the teeth of a cogwheel with the shape of recess is unanimous, and the mounting hole has been seted up to the centre of mount pad, connecting portion are formed by two sections some pin joints, one of them section tip of connecting portion and mount pad interlock, another section tip of connecting portion with nut installation head is connected. After adopting above -mentioned scheme, have a power failure in the time of can avoiding overhauing the gold utensil bolt, guarantee the?normal?power supply.