In this study, through the soil-water characteristic curve model, evaporation rate-matric suction model and moisture content-evaporation rate model, the evaporation model of tailings cemented paste was established to determine the moisture content of tailings cemented paste at different ages. According to research findings, while the concentration of tailings cemented paste is 65%, different types of tailings have little difference in change of moisture content for 1 d and 3 d, because the initial water content is higher. Tailings cemented paste with more clay content have higher moisture content for 7 d. While the concentration of tailings cemented paste is 72%, the moisture content is obviously affected by the clay content. High clay content means high clay particles, and moisture content in the tailings cemented paste is higher, which is because clay minerals reduce evaporation in the tailings cemented paste.