Abstract: Laser conducting-limited welding of thin-wall HR-2 hydrogen-resistant stainless steel (HRSS) parts is discussed,processing parameters is studied,fluctuation of penetration and its influencing factors are analyzed,and measures to control fluctuation of penetration are presented.It is found that the maximal depth of fusion can be exceeded,and the fluctuation of penetration can be lessened,by taking measures such as low welding speed and preheating,when the HR-2 HRSS is welded by CO2 laser beam conduction-limited welding.With appropriate processing parameters and measures during laser conducting-limited welding of thin-wall HR-2 HRSS parts,depth of fusion can exceed 0.25mm,its fluctuation can be controlled in scope of ±10%,and good quality of weld can be achieved.Besides,centering and tack welding by laser beam should be avoided as centering point and tack-welding point can influence weld quality largely.