Abstract: Aquatic plants play an important role in improving the water quality of eutrophic shallow lakes. Ecological restoration technologies based on the restoration of aquatic plants have been widely used in the treatment of eutrophic shallow water bodies. However, excessive reproduction of aquatic plants can release a lot of nutrients to the lake ecosystem after decomposition, which will aggravate the degree of eutrophication. Therefore, it is of great significance to study the decomposition of aquatic plants for the stability of lake ecosystem. This paper summarizes the decomposition mechanism of aquatic plants, including the decomposition process, the migration and transformation of elements in the decomposition, and the differences of decomposition of different types of aquatic plants. The effects of biological and abiotic factors on the degree and rate of aquatic plant decomposition were discussed. The effects of aquatic plant decomposition on lake ecosystems were analyzed, including direct and indirect effects on water quality, sediment characteristics, greenhouse gas emissions, and aquatic community structure. Finally, based on the current research progress, this paper puts forward suggestions and prospects for future research on the decomposition of aquatic plant residues, in order to provide scientific basis for the restoration and management of lake ecology.