The freeze-thaw (FT) erosion along with water erosion and wind erosion composed of a complete type of soil erosion. Limited by many factors, studies on evaluating the erosion quantities are rare. In this study, we comprehensively analyzed the evaluation indices of FT erosion and subsequently applied the sensitivity to soil moisture of microwave remote sensing technology for identification of FT state. We then established an estimation model suitable to evaluate the FT erosion quantity in Western Sichuan Plateau using weighted summation method of six impact factors including the annual FT cycle days, average diurnal phase-changed water content, average annual precipitation, slope, aspect and vegetation coverage. Finally, with the support of GIS, we classified FT erosion quantity in Western Sichuan Plateau. The results show that FT erosion distributes in broad areas of Western Sichuan Plateau. Different FT erosions with different intensity have evidently different spatial and geographical distributions.