Abstract: Welding of rapid-solidfied heat-resistant aluminum alloy AA8009 is very important to its application.Different welding parameter were used in the Nd:YAG laser butt welding of 1mm thick AA8009 plate.The results show that, with the welding speed increase, and the total energy input decreases, and the cooling rate within the weld increases, and the weld microstructure are improved and changed from equilibrum state to non-equilibrum state microstructure. When the energy input is 8.15 J/mm, the tensile strength reaches 379.9 MPa, that the weld coeffcient reached to 95% and the fracture happens at the boundary fusion zone.