Abstract: Based on the qualitative analysis of relationship of recharge and discharge between surface water and groundwater in Maozhou River Basin, we established SWAT and SWAT-LUD models to simulate the circulation and transformation process of watershed water, quantified the interactive volume between surface water and ground water, and estimated the pollutant contribution. The results showed that the volume of groundwater recharge to surface water was 1.6×10⁸ m³ in 2017, with the amount of NH₃-N、TP and COD at 0.9×10⁴, 0.2×10⁴ and 1.7×10⁴ t, respectively, and approximately contributed 3% of the total river pollutants; the volume of surface water recharge to groundwater was 1.0×10⁶ m³, with the amount of NH₃-N, TP and COD at 11 t, 1.1 t and 510 t, respectively, and contributed 2% of the total pollutants of groundwater recharge surface water; the amount of groundwater recharged by river water infiltration in flood area was 6.7×10⁶ m³. On the basis of above research, we suggested to adopt engineering measures, such as sediment dredging, construction of permeable reaction wall in interactive zone, building sluice on river estuary, watershed water environmental early-warning and monitoring in interactive zone, to implement joint prevention of surface water and groundwater pollution in Maozhou River Basin.