Abstract: To address agricultural non-point source pollution control and low efficiency of conventional irrigation and drainage systems, an integrated water purification-intelligent irrigation and drainage system（hereinafter referred to as the agricultural circulating water treatment system）was developed．Multi-period water quality monitoring was conducted to systematically analyze temporal variations in water quality and regulatory effects of system across different crop seasons in rice-wheat rotation area．Results showed that agricultural circulating water treatment system achieved removal rates of 24.00%～59.62% for ammonium nitrogen（NH₄⁺-N）、 7.41%～55.12% for nitrate nitrogen（NO₃⁻-N）, and 18.18%～54.73% for total nitrogen．Aeration technology increased dissolved oxygen concentrations by 52.45%～163.85%, significantly improving aquatic ecological environment．Agricultural circulating water treatment system demonstrated significant benefits in nitrogen reduction, water resource recycling, and non-point source pollution control, providing a scalable technical model for green agricultural development．