The process of YAG laser welding for 316L stainless steel and 6061 aluminum alloy was investigated, the associated process parameters of laser welding (welding current, laser pulse width, laser frequency and welding speed) were optimized, and the tensile shear strength and microhardness within the weld zone of the 316L/6061 dissimilar matels joint was analyzed. The results show that: the optimized welding current was 100 A, laser pulse width was 4.5 ms, laser frequency was 12 Hz and welding speed was 0.17 m/min; the corresponding joint tensile shear strength was 98.86 MPa; the microhardness of weld pool was between that of the aluminum alloy and stainless steel, and microhardness reduced with diverging from the weld center (from the weld center to the fusion line).