The utility model provides a locking structure of taking off of overhead wire, including earthing knife -switch, cross the lead wire, fixed frame with install dead end insulator and the suspension insulator on fixed frame, it goes between to cross links to each other with dead end insulator and suspension insulator respectively, and dead end insulator and the lead wire of crossing that links to each other with suspension insulator are equipped with the traction cable that prevented the lead wire pine and take off within a definite time. Adopt the utility model provides a structure can prevent the condition such as short circuit tripping operation that the lead wire drops and leads to, because of the utility model discloses can implement under not power failure condition to can keep running well under the situation that the lead wire breaks away from with the insulator excessively, avoid the compelled stoppage in transit of power supply line, improve service reliability. The utility model also provides an insulating of dampproof course that have as the traction cable is restricted for above -mentioned structure also can normal operating in complicated sleet weather.