Novel denitrification biofilter system

The utility model discloses a novel denitrification biofilter system and belongs to the technical field of sewage treatment. The system comprises: a distribution reservoir; the filter tank group comprises a plurality of denitrification biological filter tank assemblies; the denitrification biological filter assembly comprises a first-stage anoxic tank, a first-stage aerobic tank, a facultative tank, a second-stage anoxic tank and a second-stage aerobic tank which are communicated in sequence, and the first-stage anoxic tank is communicated with the water distribution tank; and the water outlet tank is communicated with the secondary aerobic tank. According to the utility model, denitrification is carried out through the two primary anoxic tanks, nitrate nitrogen is converted into nitrogen, and total nitrogen in sewage is removed; nitrification is carried out through a first-stage aerobic tank, and ammonia nitrogen is converted into nitrate nitrogen; then the denitrification effect is enhanced through the seco