Abstract: The main structure of a residential building has been completed. Because the basement roof was not covered with soil according to the design requirements, and there was a sudden rainstorm, the basement floated in some areas. Cracks occurred at the junction between the basement and the main building, and also occurred in some beams, walls, and columns. In this paper, combined with the actual situation of the community after floating and the original design drawings, the on-site detection and identification are carried out. This paper also makes a detailed analysis on the causes of floating accidents in the community and the cracking degree of various building components in the basement on the first and second floors, and puts forward the combined anti floating reinforcement scheme of the basement. The project has been tested in several high-water period, and the construction quality and reinforcement effect of basement anti floating reinforcement are good.