Abstract: A high-density aquaculture system was built for experiment with tilapia as the culture object for three months in this study, in order to study its regulated ability on water quality and fish growth. The system was constructed by a vertical precipitator, drum microfiltration machine, moving-bed biofilm reactor, multiple chamber spraying oxygenator, trickle degassing tower and sterilization devices, and had high performance in water treatment. The results showed that the feeding and growth of tilapia were normal under the high-density aquaculture system. The stocking density increased from 3.5 kg/m3 to 32 kg/m3 rapidly with the food coefficient of 1.72. The system had significant regulated ability on water quality, which was stable after treatment. When the amount of daily water exchange was maintained at about 5%, the temperature was maintained at 23-28.0℃, concentrations of ammonia nitrogen, nitrite nitrogen, and dissolved oxygen were 0.272, 0.067-0.21 and 7.40 mg/L, respectively, and COD was 7.15 mg/L. The results prove that applying this recirculating system in tilapia culture is feasible and efficient.