Aeolian vibration of overhead ground wire is very strong in Hexi 750 kV transmission line of Gansu province, resulting in slip of dampers, fatigue break of ground wire endangering the safe operation of transmission lines. Based on this, special dampers with preformed clamps is developed and collocated according to parameters of lines, terrain and weather conditions. For the particular areas with strong aeolian vibration, the anti-vibration device by combining damper with preformed clamps and damping wire is recommended. The new type of damper meet the standard requirements, is verified to work well by the indoor simulation experiments and field tests. The dampers have been successfully applied in Hexi 750 kV transmission line.