Ag-Sn-In alloy powders were prepared by atomization. By investigating the effect of the process parameters (sintering temperature , sintering time , compacting pressure ),we confirm the optimal sintering temperature , sintering time and compacting pressure is 950℃ for 10h and 200MPa. By the comparative study on properties and micro-structures of AgSnO2 electric contact materials prepared by the pure oxygen atmosphere sintering process and the traditional sintering process, The results indicate that a pure oxygen atmosphere is conducive to the high temperature sintering, which improves the efficiency of the sintering and eventually improves the micro-structure and performance of AgSnO2 electric contact materials.