Manual planning of city marathon routes has low efficiency. In view of this, this study adopts a greedy and backtracking algorithm to carry out intelligent planning of a city marathon route. The specific method is described as follows. A road network connected by the topological relationship of longitude and latitude coordinate points is built through the urban road network information, and a traversal search is performed by the greedy and backtracking algorithm on the coordinate points. In addition, according to the special requirements of the city marathon route, strategies are adopted, such as direct approximation, heuristic distance, heuristic approach, and direction estimation, so as to realize the intelligent planning of the route. On this basis, a marathon route evaluation method is proposed, which integrates five dimensions including POI heat value, road width suitability, route smoothness index, comfort for turning, and POI density. Finally, a comparative analysis of artificial and intelligent route planning for Beijing and Hefei marathons is carried out. The results show that the proposed method can realize fast and efficient marathon route planning.