Method for removing nitrogen and phosphorus from urban domestic sewage containing nitrogen and phosphorus

The invention discloses a method for removing nitrogen and phosphorus from urban domestic sewage containing nitrogen and phosphorus. A filtering device is arranged at the upper end of the first sedimentation tank to filter and block solid waste in the urban domestic sewage, solid and liquid in the urban domestic sewage are separated, and filtered solids are manually and regularly cleaned; preliminary sedimentation: adding a metal precipitant into a first sedimentation tank, and slowly stirring by utilizing an underwater propelling stirrer, so that the sewage is flocculated and settled in the first sedimentation tank; biological treatment: sequentially conveying the sewage subjected to primary precipitation into an anaerobic tank, an anoxic tank and an aerobic tank for biological treatment to obtain phosphorus-containing sludge and dephosphorized water; secondary sedimentation: conveying the phosphorus-containing sludge and the dephosphorized water into a second sedimentation tank through a sewage pump for sec