The photon-counting laser altimeter on the Ice,Cloud and Land Elevation 2 (ICESat-2) satellite offers a solution for tracking the dynamic water level variations in medium and large inland lakes.We utilize the monthly ATL13 global inland water data of ICESat-2 satellite from 2018 to 2020 to estimate and analyze the water level change in Poyang Lake.The measured data from Hukou,Xingzi and Kangshan hydrological stations are used for verification and error correction,and the water level and rainfall data of each station are combined to analyze the dynamic variation of Poyang Lake water level and reveal the underlying drivers.The results show that,the annual water level of Poyang Lake varied sharply with obvious seasonal variations and an overall upward trend;the high water level period was from June to October,which peaked from July to September.The linear correlation coefficient of water levels between ICESat-2 and measured data is above 0.846,rising to 0.974 after error correction.The Root Mean Square Error (RMSE) is 1.660 m,1.073 m,and 0.836 m for Hukou,Xingzi,and Kangshan stations,respectively;error correction and recalculation can decrease the RMSE to 0.663 m,0.659 m,and 0.440 m for Hukou,Xingzi,and Kangshan stations,respectively,enhancing the measurement accuracy by nearly one meter.The variation of water level in Poyang Lake is highly correlated with the change of rainfall,the reduced precipitation during periods from January to February and October to December corresponds to the declining water level in dry season,while the increased rainfall from March to October corresponds to the water level rise in wet season,and the precipitation concentration period from July to September aligns with the peak of water level in Poyang Lake.