Abstract: To explore the effect of polypropylene fiber, glass fiber and slag on mechanical properties of cemented tailings backfill, based on the range and variance analysis of the compressive strength, tensile strength and slump of the polypropylene fiber, glass fiber and slag cemented tailings backfill, the influence degree and significant influencing factors of polypropylene fiber, glass fiber and slag on the compressive strength, tensile strength and slump of the cemented tailings backfill were obtained. The results show that the influence degree of the three factors on slump is as follows: polypropylene fiber, glass fiber and slag content. These three factors are the significant factors affecting the slump of the slurry. Adding fiber and slag can improve the compressive and tensile strength of backfill. The effects of polypropylene fiber, glass fiber and slag content on the compressive strength of cemented tailings backfill are different in different curing ages. And polypropylene fiber has the most significant effect on tensile strength.