Abstract: NiTi alloy and SUS304 were successfully joined by using laser welding with Ni interlayer,and the effects of Ni interlayer thickness on the joint structure and mechanical properties were studied. The results show that the addition of Ni interlayer effectively inhibits the generation of brittle intermetallic compounds(IMC) between the base metals. The weld structure is mainly dendrites. When the thickness of the Ni interlayer changes from 0.1 mm to 0.3 mm,the content of TiCr₂ and TiFe₂ IMC in the weld decreases,the hardness of the joint decreases and the tensile strength increases,and the tensile strength of the joint reaches the maximum value of 570 MPa. When the thickness of nickel layer increases to 0.4 mm,too much TiNi₃ phase is generated in the weld,which reduces the mechanical properties of the welded joint.