Method for removing nitrogen and phosphorus from sewage and special equipment for implementing method

The invention relates to a method for removing nitrogen and phosphorus from sewage. According to the method, part of inlet water of a sewage plant directly enters a denitrifying bacterium multiplication tank, after subjected to denitrifying bacterium multiplication, a mixed solution in the denitrifying bacterium multiplication tank is added into an anaerobic tank, and the effect of nitrogen removal by denitrification of the sewage plant can be remarkably improved. Meanwhile, nitrifying bacteria are added into the anaerobic tank, so that the speed of removal by denitrification of NO3-N in returned sludge by activated sludge can be accelerated, a strict anaerobic environment can be formed in the anaerobic tank, anaerobic and aerobic biological phosphorus removal of the activated sludge is facilitated, and the biological phosphorous removal effect of the sewage plant can be improved. The invention also provides special equipment for implementing the method. The special equipment comprises a grit chamber, an anae