Abstract: Experimental study was carried out with three laser devices of two type of laser device.The results show that the oxide of on the 1420 Al-Li alloy surface will make for pores in the process of laser welding, and the pores can be decreased by chemic cleaning to the surface.The numbers of pores have something to do with the sort of gas, the shielding gas flux, and the welding speed.As last, 1420 Al-Li alloy weld without porosity and with good appearance was oblained by adopting dual laser beams welding.