The invention discloses a method fpr 
coupling denitrifying dephosphatation and partial 
nitrification, and belongs to the field of municipal 
wastewater treatment. Firstly, 
raw water enters an (A / A / O)-SBR reactor; carbon pick-up synthesis polyhydroxyalkanoate (PHA) and 
phosphorus release reaction at an anaerobic phase are carried out; oxidation-
reduction potential (ORP) is controlled at -30mv to -240mv; dissolved 
oxygen (DO) is smaller than or equal to 0.2mg / L, and then nitrifying 
reflux liquid containing NO2<-> from N-SBR is injected to carry out anaerobic denitrifying dephosphorization reaction; the ORP is controlled at -90mv to -210mv; the DO is smaller than or equal to 0.2mg / L. The flow of the nitrifying 
reflux liquid is adjusted at the stage according to the anaerobic 
phosphorus-release condition. The transient 
aeration, 
nitrogen stripping and aerobic 
phosphorus absorption are carried out after complete reaction; the DO is controlled to 2-3mg / L; sediments are stilled; discharged water enters the N-SBR reactor to carry out aerobic 
aeration. 
Nitration is controlled at a short-range stage through an '
ammonia valley' on a pH curve and an '
ammonia-
nitrogen jump point' on a DO curve in the process; still deposition is carried out after the reaction is ended; a part of supernate is returned and the other part is discharged; the discharged water quantity is equal to the initial water inflow of the 
system. The denitrifying dephosphatation principle and the partial 
nitrification principle are applied, 
energy conservation and consumption reduction are achieved, and the method is applicable to a domestic 
wastewater with low C / N ratio, so as to achieve a synchronous and deep 
nitrogen and phosphorus removal effect.