By the first-principles plane-wave pseudopotential method based on the density functional theory, the effects of pressure on the electronic structure and mechanical properties of γ'-Ni3Pt were studied. The first-principles calculations have been carried out on γ'-Ni3Pt as a function of pressure from 0 to 50 GPa with a step 5 GPa. The results indicate that the equilibrium lattice parameters under zero pressure are consistent with other experimental and theoretical data. The calculated total density of states and partial density of states under different pressures show that the compound exhibits metallic properties, and the stability of system increases first and then decreases with the increase of pressure. In addition, the bulk modulus (B), shear modulus (G), Young's modulus (E) and Poisson's ratio (υ) of Ni3Pt were calculated by the Voigt-Reuss-Hill method (VRH). It's found that the hardness and ductility of crystal are improved as the pressure increases. In short, it's calculated that the pressure has a marked impact on the electronic structure and mechanical properties of Ni3Pt.