Abstract: Dissimilar metals of 304 stainless steel and 5052 aluminum alloy were connected by Nd: YAG laser welding. The welding test was carried out among different parameters, such as peak power, welding speed, defocus and pulse frequency. The surface morphology of three different welds was discussed, and the trend of the weld height with the process parameters was explored. The process parameter interval of three surface topography of steel-aluminum weld is obtained. The results shows, the surface topography of the weld is determined by factors such as the laser single point energy and defocus, and here is an intrinsic link between weld height and welding process parameters.