Ii is an important way of achieving steel slag large-scale effective utilization that steel slag used as the supplementary cementitious materials.However, the activity of steel slag is very low, it is a key problem that how to improve the cementitious property of steel slag.Chemical excitation is an effective measure to improve activity of cementitious materials, so seven kinds of chemical admixtures including alkali metal salts and organic alcohol amines were selected in this article.The effects of these chemical admixtures on the paste strength, activity index of steel slag, and mortar strength of blended cement containing steel slag were studied,and the microscopic mechanism was also analyzed by XRD, SEM and TG.