The IC10 single crystal superalloys are welded by the laser welding process, and the effects of welding speed on joint weld forming, cross-section morphology and microstructure are analyzed. The results show that the surface and back widths of welds increase with the decrease of welding speed. The cross-sections of welds under different welding speeds all show a typical goblet shape. The welds mainly consist of fine grains, cellular crystals and columnar crystals. The welding cracks extending along the grain boundaries always occur in welds under different welding speeds. The growing direction of the grains in joints tends to be the same, which increases the cracking susceptibility of joints.