Based on the measured water and sand data of Hukou hydrological station from 2012 to 2021, the basic characteristics and change trend of water and sand at the outlet of Poyang lake in the past decade and the reasons for the change were preliminarily analyzed.The results showed that the amount of sand transport out of Poyang lake showed a decreasing trend in the past decade, and the annual sand transport and sand content of Poyang lake showed obvious mutation points around 2017.The amount of water and sand flowing into Poyang lake from the Yangtze river showed a decreasing trend, which affected the distribution of outflow runoff and sand transport during the year, but had a weak impact on the annual water volume and sand transport volume of Poyang lake.Sand mining activities and river erosion in Poyang lake area have a great impact on the amount of sand transported out of the lake.