Based on the first principles, the physical parameters such as point defect formation enthalpy H, elastic constants C₁₁, C₁₂, C₄₄, bulk modulus B, shear modulus G, Young's modulus E and Poisson's ratio γ that characterize the strength and toughness of materials in Ag-based alloys doped with alloying elements such as Cu, Zr, W, Cr, Sn, Ni, In, Zn, Ir were calculated in this paper. The difficulty of doping different alloy atoms in Ag matrix and the effects of the valence electron difference ΔV between the alloy atom and the Ag atom on the elastic properties of the Ag-based alloy were analyzed. With the increase of the ΔV, the ability of Ag-based alloys to resist plastic deformation, shear deformation and maintain crystal structure stability during shear deformation can be enhanced. Furthermore, differential charge density of Ag-based alloy projected on the {1 0 0} plane shows the spatial distribution of charge transfer before and after bonding. It is found that the enhanced elastic properties of Ag-base alloy can be attributed to the strong bonding between the alloy atom and Ag atom.