Biological filter device for sewage treatment

The invention relates to the field of environmental engineering, particularly a biological filter device for sewage treatment. The technical scheme is as follows: the biological filter device for sewage treatment is characterized by comprising a relatively closed biological filter and a water discharge tank, wherein the biological filter is provided with a water inlet pipe, a gas inlet pipe, an updraft gas outlet pipe and an overflow pipe; a water distribution device, filler-containing filter containers, a water circulator and a water discharge device are arranged in the biological filter; the filler-containing filter containers are arranged in the biological filter at intervals; a water outlet of the water distribution device is faced with the filler-containing filter containers; water of the water discharge device is discharged into the water discharge tank; and the water discharge tank is provided with a solar power electrocatalytic oxidization disinfection device. The novel biological filter device for sewage treatment has a simple structure; and the inside of the filer has different types of oxidization states and different sewage stream flow modes.