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By using Ag powder and nano-SnO₂ as raw materials , Ag/SnO₂ electrical contact materials and its rivets were prepared by mechanical alloying and hot extrusion and cold press-welding process. The phase composition of the commercial Ag powder and as-prepared SnO₂ and Ag/SnO₂ composite powders was analyzed by X-ray diffractometry (XRD). The surface morphology and arcing characteristics and mass loss of the rivets before and after the electrical life test were characterized by Scanning Electron Microscopy (SEM). Effects of different process parameters (working current and cycle number) on the arcing characteristics, arc eroded morphology, mass loss and degradation mode of Ag/SnO₂contacts were analyzed comparedly..The results showed that compared with pure Ag, Ag/SnO₂ electrical contacts had higher arcing time and arcing energy under arcing, and the average arcing time of making-arc and breaking-arc was 25.86ms and 51.78ms, which was 2.78ms and 4.87ms higher than that of pure silver, respectively; the average arcing energy of making-arc and breaking-arc was 493.85mJ and 988.14mJ, which was 58.76mJ and 104.93mJ higher than that of pure silver, respectively. As the number of cycle operations increased, the total mass loss of the Ag/SnO₂ electrical contacts was negative value, and its main failure degradation modes of droplet splatter and SnO₂ particles floating were manifested.