During the design process of the asymmetric-paths winding, the optimization between the asymmetric degree and the tidiness of end connections is still a difficulty for the existing methods. In this paper, the connection indices are proposed for the connection evaluation. In addition, a novel directed graph approach is provided for the connection optimization. It turns the connection design into the route optimization of the directed graph, including the modeling of the winding directed graph, the searching rules for a parallel path, and the matching rules between parallel paths. The winding design of a hydrogenerator is presented for the validation. The results show that the optimized scheme presents a tidy end connection, shorter circumferential busses, and a good performance in the electromagnetic field. This approach provides a new idea for the modeling of ac windings and the optimization design of the asymmetric-paths winding.