Fly ash and iron tailings were used as main raw materials, and a novel zeolitization ceramsite was successfully prepared by high temperature sintering activation-hydrothermal synthesis process. Basic ceramsite was obtained by high temperature sintering while activating inert phases such as mullite in the raw materials, then the zeolite modification of the basic ceramsite by hydrothermal reaction was carried out to increase the specific surface area and adsorption capacity of ammonia nitrogen. The results show that the optimum preparation conditions are as follows: m(fly ash)∶m(iron tailings)∶m(quartz sand)=7∶1∶2, sintering temperature is 1 040 ℃, sintering time is 30 min, NaOH solution concentration is 15 mol/L, hydrothermal temperature is 160 ℃, hydrothermal time is 12 h. XRD, SEM, FT-IR and Raman tests show that the main crystal phase of the zeolitization ceramsite is zeolite P and analcime. And its specific surface area increases from 1.068 m2/g of the basic ceramsite to 35.770 m2/g, and the maximum adsorption capacity for NH+4-N increases from 1.82 mg/g of the basic ceramsite to 13.34 mg/g, which increase to 33.49 times and 7.33 times of the basic ceramsite, respectively. The present results of this experiment show that zeolitization ceramsite has potential applications in wastewater treatment.