In order to study the temporal and spatial distribution characteristics of water exchange capacity of Hongze Lake, a two-dimensional hydrodynamic model of Hongze Lake was established based on MIKE21, and the water exchange cycles in different lake areas of Hongze Lake were simulated and analyzed. Considering the dual characteristics of wind-driven flow and throughput flow in the flow field of Hongze Lake, the spatial variation characteristics of water exchange period in different seasons and different wind fields were analyzed. The results show that the spatial heterogeneity of water exchange period in Hongze Lake is obvious, increasing from south to north. The average water change cycle of the whole lake is longer in winter and spring, which are 75.d and 60.d respectively, and shorter in autumn and summer, which are 49.d and 31.d respectively. The actual wind field has a positive effect on the water exchange capacity of Hongze Lake, the southeast wind has a positive effect on the water exchange capacity of Hongze Lake, and the northeast wind has an inhibitory effect on the water exchange capacity of Hongze Lake.