From the laser filler wire welding tests to the 5A06 aluminum alloy sheet of 1.2mm thick,we found that the impossible realization of the effective welding process parameters by using laser welding when the welding speed is low can be realized by filling wire so that get the better deep penetration welding result.There are only few tiny blowholes in the welding seam.This paper also analyzes the welding effect and the forming mechanism of the blowhole.The laser welding with filler wire can increase the laser energy absorption rate of the materials through adding wires,to maintain the relative stability of the blowhole,to improve the welding seam forming by using laser welding in the lower welding speed,thus can realize the one side welding and double-side shape of the welding seam.