The utility model discloses an overhang ground wire insulator, which comprises an upper electrode and a lower electrode; the upper electrode is fixed on a steel cap through a first collar clamp, a first screw nut and a first screw bolt; and the lower electrode is fixed on a steel foot through a welding collar clamp, a second screw nut, a second screw bolt and an elastic gasket. The overhang ground wire insulator is characterized in that a plurality of grooves are formed on the outer circumference of the steel cap; and a steel bar is arranged on the inner side of the first collar clamp and clamped in any groove. The utility model changes the manner in the prior art that the size of the gap is manually controlled, and utilizes the matching of the grooves formed on the steel cap and the steel bar at the first collar clamp, thereby improving the working efficiency of field assembly, ensuring the working stability of the gap, and better realizing safe and stable operation of the transmission line.