The catalysts were prepared by loading metal ion of the iron ore waste tailings on g-Al2O3 supporter by impregnation method and characterized, and their catalytic performance on the removal efficiency of formaldehyde was studied in a quartz glass fixed bed reactor. The results show that for the catalyst calcined at 450℃, the crystallinity of g-Al2O3 supporter is good and Fe2O3 highly dispersed in the supporter with the specific surface area of 214.87 m2/g. While the performance of modified catalyst doping Ag+ is improved with the specific surface area increased to 237.70 m2/g. The catalyst calcined at 450℃ has the highest formaldehyde conversion efficiency of 67%, which means the high catalytic activity. Furthermore, the doping of Ag+ in catalyst can make the formaldehyde conversion efficiency raise over 10%. With the increase of reaction temperature, the conversion efficiency of formaldehyde increases accordingly. This indicates that it is feasible to use the catalyst prepared by iron ore tailings for removal of formaldehyde.