In this experiment, we used 7-kW continuous wave (CW) CO_(2) low order mode laser and YAG impulse laser to deeply weld high-speed steel (W18Cr4V) and spring steel (65Mn). To welded joint, we analyzed its microstructure, micro hardness and fracture appearance for different welding technology by metallography microscope, scanning electron microscopy and bending strength test, discussed its action of fracture and the relation between its structural transformation and strength. At last, we offered an optimum welding technology having no welding defect by the comparison and analysis of processing property.