With the rapid development of urban subway construction, many city subway lines have been networked.Considering the public welfare when making ticket price, most cities in China calculate the ticket price between the two stations of the line network by the shortest path or the least stations now. the traditional Dijkstra algorithm was improved based on the traditional Dijkstra algorithm. The traditional Dijkstra algorithm and the improved Dijkstra algorithm were respectively used to calculate the shortest walking route of Changsha metro line 1~5 network. Results show that the improved Dijkstra algorithm not only effectively improves the efficiency of the algorithm and overcomes the long-time defect of the traditional algorithm, but also partly eliminate the accumulated errors between lines and improve the ductility of the network.