This study carried out an investigation on macrophytes of Lake Qionghai in July and December 2021, and May and September 2022. Based on the investigation results and previous publications, this study examined the species compositions, community structure, spatial distribution, and causes of degradation of macrophytes. The investigation revealed that there were 23 species of macrophytes in Lake Qionghai, mainly found in water area less than 2 m deep, covering an area of about 1.3 km². The distribution of macrophytes was mainly in the north, with patchy distribution in the west and south, and scattered in the east. However, the areas had decreased to less than 5% of the lake from 20% before the 1990s. The community structure of submerged plants had become simplified, while the distribution ranges of floating plants and emergent plants expanded. The disappearance of submerged vegetation in Gaojian Bay was caused by a flood from the mouth of the Hai River in 1998. Additionally, higher water-level operations and lower transparency in the last ten years had resulted in the decreased distribution areas and simplified communities of macrophytes in Lake Qionghai. To restore the macrophytes in Lake Qionghai, we recommend implementing measures to restore the natural rhythm of the water level and reduce pollution load input to improve water transparency. At the same time, artificial ecological restoration is also needed to restore the ecosystem's health.