Abstract: (Purpose) The Four-Lake Basin in the Jianghan Plain is a typical river-lake-wetland-farmland multi-element system in the middle reaches of the Yangtze River, facing prominent eco-environmental challenges. To accurately quantify the exchange rates between major water systems and groundwater in the basin and to analyze the main factors influencing the degree of soil gleyization, (Method) this study constructed a loosely coupled surface water-groundwater model for the Four-Lake Basin using SWAT-MODFLOW. Based on the simulation results, the spatiotemporal variation in surface water-groundwater exchange rates and the distribution of cold waterlogged paddy field were systematically examined. (Results and Conclusion) The results show that the coupled model performs well in simulating both runoff and groundwater dynamics. The exchange between the Yangtze River and groundwater exhibits clear seasonal reversals: river water recharges groundwater in spring and summer, while groundwater discharges into the river in autumn and winter. Within the basin, the interaction intensity of Chang Lake is higher than that of Hong Lake, and the main canal shows different exchange patterns between its upstream and downstream sections.The risk areas of soil gleyization (groundwater depth < 3 m) are mainly distributed around Honghu Lake, along the Four-Lake main canal, and in the northwest of Jianli City, influenced jointly by rainfall infiltration, topography, and land-soil types. This study provides a quantitative basis for understanding water exchange processes and soil waterlogging risks in the Four-Lake Basin, offering scientific support for regional water resources management and ecological conservation.