Existing skeleton extraction methods, however, are often sensitive to noises and disconnected. This paper proposed a skeleton extraction method based on Poisson equation. It can approximate the topology structure of the input 3D model well, and avoid the broken lines. First, the proposed method extracts critical points of a 3D model by using Poisson equation and geodesic distance. Then the extracted critical points are connected and star skeleton of the 3D model is defined. Finally, the reverse force filed based Poisson energy distribution is used to push star skeleton into final result. Experiments show that the extracted skeleton is continuous and has no small branches affected model noises.