Multistage continuous bioreactor

The invention belongs to the technical field of sewage treatment devices, and particularly relates to a multi-stage continuous bioreactor which comprises an anaerobic biofilter arranged at the lower end of the middle part, the internal circulation nitrification and denitrification area is arranged at the upper end of the middle part; the lower end of the water inlet pipeline extends to the bottom of the anaerobic biofilter; the two aerobic biofilters are symmetrically arranged on the two sides of the middle part; the solid-liquid separation tank is arranged on the outer side of the aerobic biological filter tank; the aeration device is arranged at the bottom of the aerobic biological filter; and the sludge discharge pipe is arranged below the flow guide plate. The multi-stage continuous bioreactor integrates the advantages of an activated sludge method, a biofilm method and an immobilized microorganism technology, the immobilized technology of microorganisms and carriers is adopted, the survived microorganism