The utility model discloses an important leap regional security of transmission of electricity overhead earth wire protects connecting device fully, its technical scheme is: tip at overhead earth wire sets up the fixed fastener of primary load bearing, it is articulated that the fixed fastener of this primary load bearing passes through U type link and connecting bolt and transmission tower fixed plate, set up reserve protector simultaneously on being close to transmission tower's overhead earth wire, this reserve protector includes fixed fastener of reserve and extension rod, wherein, the fixed fastener of reserve is in the same place with the overhead earth wire fastening, furthermore, the fixed fastener of this reserve is articulated with the one end of connecting plate, the other end of this connecting plate is articulated with the one end of extension rod, the other end of extension rod passes through the connecting piece and is connected with the transmission tower fixed plate, thereby it connects to form dual -protection. The utility model discloses effectively reduce transmission line fault trip number of times, reduced the power system blackouts time, improved mains supply quality and customer satisfaction.