In this study, the wind-wave model SWAN was used to simulate the characteristics of variations and distributions of wind waves in Lake Chaohu for the year 2018. The model was calibrated and evaluated using observational data. Results suggest that the annual mean significant wave height and wave period of Lake Chaohu during 2018 were 0.16 m and 1.26 s, respectively. The wind wave was strong in spring and weak in autumn. The monthly mean values exhibit great variations. The largest monthly values of 0.22 m and 1.36 s were obtained in April, while these values were 0.11 m and 1.06 s in November, which were the lowest during 2018 and whose variation ranges were 52% and 22% of the maximum values, respectively. Among different lake basins, monthly mean wave height in the east basin and central basin were the highest, followed by the west basin. The highest value of monthly maximum significant wave height and wave period appeared in the east basin or the central basin. The values of monthly maximum significant wave height and wave period varied significantly during different months, whose variation ranges were 61% and 27% of the maximum values, respectively. The distribution ratio of the high values of monthly significant wave height and wave period computed by model in different lake zones were large in the east basin or central basin, but it was small in the west basin. The proportion of time when the high significant wave height appeared was different during different months in different lake zones, and it was small from September to November, which would be beneficial to the emergence of cyanobacteria blooms.