Aiming at the problem of black-odor, oxygen deficiency and ammonia-nitrogen pollution of polluted rivers, a new type ofecological floating bed—micro-aerated ecological floating bed was developed, which combined biofilm packing, floating aquaticmacrophyte and auxiliary aeration device. The purification efficiency of the polluted river water was studied by the model experimentin the outlet of Daqing River. The results showed when the hydraulic loading was 1500mm/d, the mean removal efficiencies of totalnitrogen, ammonia nitrogen, total phosphorus and phosphate were 81.1%, 91.3%, 72.7% and 92.5%, respectively. Additionally, thefloating bed showed better removal effect on organic matters. The cost of micro-aerated system to treat 1m³ of polluted river waterwas only 0.007 Yuan. The micro-aerated ecological floating bed ran steadily, had a high efficiency of pollutants removal and lowenergy consumption. It was suitable for the environment of flowing water, which could be used in polluted river and estuary.