As a large shallow lake, Lake Taihu exhibits significant differences in flow structures and hydraulic factor at water-soil interface due to different terrains in lake-bay, coastal and center area. Sediment release under different flow velocities from three sites in Lake Taihu was simulating in a rectangle flume to study sediment resuspension under various hydrodynamic conditions. Combined with the in-situ test and experiment in the laboratory, a 2-D model of water flow and water quality on wind-driven current in Lake Taihu was established. The sediment resuspension flux and settling flux from different lake regions in the four seasons were calculated and the relationships between these fluxes and wind speed were obtained. The experiment result was applied in the numerical model and the suspension-sedimentation process was decomposed and generalized according to the critical wind speed. Annual average release amount of internal load in Lake Taihu during the year 2009 was estimated. The results indicate that daily release amount of internal load in Lake Taihu was significantly influenced by wind and had the same trend of change with wind. Lake Taihu has an annual average release amount of internal load with suspended solid 47.81×10⁴ t, COD 2.06×10⁴ t, total nitrogen 1149.05 t and total phosphorus 564.35 t, of which summer has the markedly higher release amount than other seasons.