This device combines the two basic functions of physical filtration and biological purification to integrate and structural design for integration,and was tested in the RAS.The results indicate that the TSS removal rate was (58.5 ± 17.8) % ;the toxic substances in water were controlled at low concentrations,i.e.,NH ₄⁺-N≤2 mg /L,NO ₂^-N ≤0.5 mg /L.During the two month experiment,fish grew well,its breeding density was increased from the test primary of 27.22 kg /m₃ to the test end of 35.20 kg /m₃,growth rate averaged 34.6%, weight specific growth rate of 0.496% /d,the survival rate of 95.9%. The study shows that the device has both of the physical filtration and biological purification function,can be well used in highdensity culture systems;it has a simple structure and it can well remove the solid particulate matter effectively,reducing backwashing structure and the loss of backwashing water;with intermittent operational characteristics,it has low power consumption.This device streamlined recirculating aquaculture system equipment,reduces power consumption,and achieved a good water treatment.