In this paper,the laser transmission joint strength is studied with semiconductor laser based on the surface pitting of 304 stainless steel and PA66.Unevenly distributed pits are formed on the surface of 304 stainless steel with 10% ferric chloride solution for two hours, which have certain morphology, depth and size. Different laser power, welding speed and welding pressure are used in laser transmission joining 304 stainless steel and PA66,which 304 stainless steel contains pitting corrosion before and after. The tensile strength test of joined samples shows that: the joint strength of pitted 304 stainless steel and PA66 with laser transmission joining is improved at least 135%; the riveted structure formed at the joining interface improve the joint strength.