Abstract: Geopolymers are prepared using low-silicon iron tailings as the main raw materials and metakaolin as the aluminum and silicium addition materials, under the condition of composite alkali excitation with NaOH and sodium silicate.The effects of different silicon to aluminum molar ration(SiO₂)/n(Al₂O₃), liquid-solid ratio, alkali activator modulus and curing condition on the mechanical strength of geopolymers are investigated, and the prepared sample with curing ages of 3-day,7-day and 28-day are characterized by X-ray diffraction analysis(XRD),Fourier infrared spectrometer analysis(FTIR) and scanning electron microscope analysis(SEM).The results show that when silicon to aluminum molar ratio n(SiO₂)/n(Al₂O₃) is 2.75, liquid-solid ratio is 0.30, the modulus of the alkali activator is 1.4, and cures at room temperature in sealing bag,the 28-day compressive strength of the prepared geopolymers is up to 72.3 MPa.Microscopic analysis shows that there are a large number of amorphous N—A—S—H gel phase and C—S—H gel phase in the sample, which closely bonds various mineral crystals together and filled the pores of the particles to form a dense structure and enhanced the sample's mechanical properties.