In order to solve the problem that China has not fully understood the water environment change of medium and small lakes and reservoirs for a long time, and the related products are still scarce, a mapping strategy of water transparency with a resolution of 30 m was proposed, and a long-time series lake water transparency dataset LAWSD30 with a resolution of 30m in China was developed. The temporal resolution of the dataset is every three years, and the spatial resolution is 30m. It is raster data,