Abstract: The autonomous localization of initial welding position of weld is one of the key technologies to realize the intellectualized welding.This paper presented a practical system and method to guide the welding robot to the initial welding position of weld.In this system,welding robot can be guided to the initial welding position of any planar weld automatically by the aid of a charge coupled device camera.Aluminium and its alloy can reflect the light strongly,which make the recognition more difficult.Taking butt joint weld of planar curve aluminium sheet as example,the autonomous localization function is realized accurately.This method is simple,practical,jarless and strong anti-jamming.And experimental results show that it has higher accuracy rate and precision,and it can meet the requirements of production.