The invention discloses a treatment system for removing ammonia nitrogen in domestic wastewater. The system comprises a water collecting well, a coarse rack, a primary sedimentation tank, a pH value regulating tank, a crosslinked polyethylene pyrrolidone carrier adsorption purification system, an aeration tank, a biological dephosphorization tank, a secondary sedimentation tank, a water purifying tank and an acid scrubbing tower. The system creatively utilizes the selective adsorptivity of the crosslinked polyethylene pyrrolidone (PVPP) for ammonia nitrogen in water, and the carbonyl groups in the molecular structure can be compounded with amino groups to form a hydrogen bond complex. Artificial zeolite containing the PVPP is mixed with domestic wastewater to sufficiently adsorb the ammonia nitrogen in the domestic wastewater, a heating desorotion mode is adopted to enable the PVPP to release the adsorbed ammonia nitrogen in the form of ammonia gas, and the tail gas is subjected to acid scrubbing purification and discharged. Meanwhle, the domestic wastewater, which is adsorbed by the PVPP-artificial zeolite carrier to remove ammonia nitrogen, enters the next treatment link.