Abstract: The 1.5 mm thick 6061 aluminum alloy and the 2 mm thick 316 L stainless steel are lap welded,and the selected welding wire is4043 aluminum silicon welding wire. Scanning electron microscopy,energy dispersive spectroscopy,X-ray diffractometer,microhardness tester and universal tensile testing maching were used to study the influence of welding parameters on weld appearance,interface microstructure and mechanical properties of the joint. The results show that welding parameters have significant effects on the macroscopic morphology of welded joints. The intermetallic phase of FeAl₃ and Fe₂Al₅ are inevitably formed in the brazed interface layer. In tensile shear tests,the specimen breaks at the intermetallic compounds layer. If the thickness of the intermetallic compounds layer is too large or too small,the tensile strength of the welded joint will be affected. At the thickness of 1.5 μm,the strength of the specimen can reach 50 MPa.