Abstract: The （TiO₂+A） catalyst was developed by immobilizing TiO₂ and active material A on brick pieces. The degradation of ammonia nitrogen wastewater was investigated by （TiO₂+A） catalyst, and the photocatalytic reaction kinetic discussed. The results indicated that the （TiO₂+A） catalyst shows high efficiency in photocatalytic oxidizing of simulation ammonia nitrogen wastewater, whose removal rate reached 95% when the reaction time is 24 h. The degradation reaction is first order. The photocatalytic activity of （TiO₂+A） catalyst is high, the active materials do not run off, and the manufacture is easy. According to the degradation experiment of ammonia nitrogen wastewater at one chemical fertilizer plant, the ammonia nitrogen can be reduced from 238 mg/L to 8 mg/L in 8 h, with the degradation rate of 97%.