Abstract: 60 NiTi (60wt%Ni-40wt%Ti) alloy presents higher hardness, high elastic modulus, good abrasion performance and excellent corrosion resistance, making it suitable for various applications in different fields. This paper investigated the microstructure and phase composition of NiTi alloy coating on 316L stainless steel prepared by laser cladding. It shows that the main alloying elements Fe and Cr in the substrate are significantly doped into the cladding coating, which obviously affect the microstructure and properties of Ni-Ti coating. The main phases in the coating are NiTi and Ni₃Ti phases. Increase the content of Ni can inhibit the precipitation of NiTi₂. First-principles calculation based on density functional theory was used to study the phase preference and site preference occupations of the alloying elements Fe and Cr from substrate in NiTi and Ni₃Ti phases. The microstructure and phase composition of the coatings were investigated as well. The results show that, NiTi and Ni₃Ti are the major phases in the coating. Both Fe and Cr atoms prefer to substitute Ni atom in the NiTi (B2) crystal structure. However, in the Ni₃Ti crystal structure, each Ni and Ti atom has two different crystal positions, Fe atom prefers to substitute position Ni-1 and Cr atom prefers to substitute position Ni-2 instead. Combined the experiment and calculation results, the major phases in the coatings after element doping are supposed to be Ni₅Ti₈Fe₂Cr and Ni₉Ti₄Fe₂Cr.