The Bi-doped nanocomposite AgSnO2 contact alloys were prepared by sol-gel method and breaking arc experiments were carried out. The morphology of the arc erosion, arc energy and arc duration of AgSnO2 contact alloys was observed and investigated by means of Scanning Electron Microscopy (SEM). Results show that the addition of Bi element improves the wettability of Ag to SnO2 and prevents the temperature arising owing to the formation of SnO2 insulation layer and thus significantly improves the electrical properties, such as the electrical life, anti-fusion welding ability, and electrical arc resistance of the materials