Routing selecting method capable of providing long connection service in VANET (gradient node-based vehicular ad hoc network)

The invention discloses a routing selecting method capable of providing long connection service in VANET (gradient node-based vehicular ad hoc network). The routing selecting method sequentially comprises the steps of route discovery, route reply, route setup and route keep-in. A destination node can acquire multiple route paths from a source node to the destination node by the source node through broadcasting, while the route paths are replied to the source node, the destination node screens out a link with the longest network service time under a condition of giving priority to the route hop counts based on the node-to-node motion mode similarity, the distance and other information, the source node can acquire the optimal route forwarding path while the route relay of the destination node is received and is not required to performing screening on the route paths, and therefore, the method is simple, rapid and effective.