The effects of high pressure on mechanical properties and electronic structures of Ni-Mo binary compounds (Ni4Mo、Ni3Mo(DOa)、Ni3Mo(DO22)、Ni2Mo) have been studied by first-principles calculation based on density functional theory method.Studies have shown that：The values of V/V0 decrease with pressure and the rates of change decrease gradually. The formation enthalpy are negative, and decrease with pressure.Thus high pressure can improve the ability of alloying.The calculated results of bulk modulus B、shear modulus G、Young"s modulus E、Lama constant λ and Hardness H illustrate that pressure can improve the resistance to deformation、compression resistance and hardness of four compounds. In addition,ratio of bulk modulus to shear modulus B/G and poisson"s ratio ν shows that all the considered compounds are ductile materials.The state density are also analyzed to explain the physical origin of the pressure effect on four compounds.Thus suggests that increasing pressure can improve?the stability and hardness of all compounds.