With the development of the country and society, people pay more and more attention to the ecological environment. In the process of economic development, there are a large number of abandoned pits left by mining, and the treatment of these pits is urgent. As an effective method for treating high, steep and smooth rock walls, the floating platform is widely used in practice. However, most analysis of the stability of the platform is based on simple formula. In this paper, a kind of concrete floating platform structure suitable for the treatment of steep rock walls in mines is designed, and the formula for calculating the stability of the floating platform is refined, and the stability of the floating platform is analyzed by combining with FLAC3D numerical simulation software. The research results show that the concrete floating platform is more practical for the treatment of steep rock walls in mines.