The essence of the technology is to fill the bioreactor with fillers. The oxygenated sewage immerses all the fillers and flows through the fillers at a certain flow rate. The filler is covered with biofilms, and the sewage is in extensive contact with the biofilms. With the metabolism of microorganisms on the biofilms, organic pollutants in the sewage are removed and the sewage is purified. This project is used to treat domestic wastewater. The tank body is made of enamel assembled tank with filler and aeration system in the tank.