In allusion to the research problems of path avoidance and multi-vehicles path conflicts during the path planning process of ground unmanned driving in unstructured environments, a shorter time-consuming path planning algorithm based on the A* algorithm under topology constraints is proposed by using homology and de Rham cohomology to accurately describe the topological information of obstacles. The algorithm realizes the topological classification of the global paths of multi-vehicles in unstructured environments, thereby providing a new research idea for the collaborative planning of multiple ground unmanned vehicles. Furthermore, combined with the topological separation characteristics of paths on the C-space dynamic generalized Voronoi diagram(GVD), an efficient algorithm called C-space-GVD-${h_S