Silver-based electrical contact materials are the core of low-voltage electrical connection in the fields of new energy power vehicles, industrial electrical appliances and other fields, with the widest range of applications and the largest demand. The Ag/SnO2 contact material system has made great progress due to its excellent electrical contact performance and arc erosion resistance. However, the material system still has problems such as higher temperature rise and shorter electrical life under service. Once it fails, it will lead to major safety accidents such as power system paralysis and out-of-control communication facilities, and economic and social losses are difficult to estimate. Herein, in order to explore the impact of the type and content of the modified components on the preparation process, microstructure, microhardness, temperature rise and electrical life of the modified Ag/SnO2In2O3 contact materials, the modified AgSnIn alloys are synthesized by medium-frequency smelting and casting process, and then the corresponding Ag/SnO2In2O3 contact materials are prepared by internal oxidation method. The AC-4 electrical life type testing platform is used to evaluate the temperature rise and electrical life performance of the materials. The results shows that the optimum parameters of internal oxidation process of the modified Ag/SnO2In2O3 materials are 700℃, 5MPa, 48h. Compared with the binary modification of Ni, Cu or Zn, there exists larger micro-strain in the Ni-Cu-Zn ternary modified AgSnIn alloys, and the microhardness of the corresponding modified Ag/SnO2In2O3 material increases first and then decreases sharply with indium content decreased. The modified AgSnIn alloy, composed of 0.47wt.% nickel, 0.4wt.% copper, 0.43wt.% zinc and 2.1wt.% indium element, could achieve complete internal oxidation. The corresponding modified Ag/SnO2In2O3 material presents the optimum microhardness (1382.49 MPa), the longest cycle number (28989 operations) and the appropriate temperature rise (43.69 K), which is attributed to some larger micro-strain (19×10-3) and grain boundary structure with strengthening effect. By comparison analysis, A positive correlation has been established between the electric life cycle number and the microhardness of the modified Ag/SnO2 material Within In element content ranged from 2.1 to 3.1 wt.%, which will provide a new idea for the formulation design and electric life performance prediction of the Ag/SnO2 contact material.