Biological filter tower for sewage deep treatment

The biological filter tower for deep sewage treatment consists of relatively independent sewage treating units with different treating targets. In the sewage flowing direction of sewage pre-treated in the anaerobic tank, there are BOD degrading filter tower, ammonia nitrogen adsorbing nitrification filter tower, the first anaerobic tank, the second anaerobic tank, soil adsorbing filter tower, and reinforcing phosphate adsorbing filter tower. There are water distributor connected to the water inlet pipe in the top of the BOD degrading filter tower and water outlet pipe connected to the bottom of the reinforcing phosphate adsorbing filter tower. The present invention has deep sewage treating capacity.