Abstract: In order to explore the effect of drying curing time at high temperature on the strength of iron tailing cement mortar,the effect of drying curing time on the mechanical properties of specimens under different iron tailing grinding time was studied,and the types,quantity and structural characteristics of hydration products were analyzed by XRD,SEM and EDS.The results showed that∶① Pozzolanic activity of iron tailings can be stimulated by dry curing at 60 ℃,and the mechanical properties of specimens are directly proportional to curing time.Adding iron tailings with grinding time of 1 h and dry curing at 60 ℃ for 16 h,the flexural strength and compressive strength of iron tailings cement mortar can reach 9.29 MPa and 40.46 MPa.② High temperature dry curing time has no effect on the types of hydration products of iron tailing cement slurry;but has an effect on the structure and quantity of hydration products and the coverage degree of hydration products.With the increase of dry curing time at high temperature,the length and quantity of C—S—H fiber increased,the value of Ca/Si decreased,the consumption of Ca(OH)2 became more intense,and the hydration products became denser obviously with almost no harmful pores on the surface.