The invention relates to a road network information collection method under a vehicle-mounted self-organizing network RSU missing scene. The method comprises: if the vehicle node is not in the communication range of the RSU, judging which intersection in the two intersections the vehicle is closer to, finding a relay node closest to the vehicle on the closer intersection, transmitting the data packet to the relay node, transmitting the relay node to an upper-layer relay node, and transmitting the data packet to the Sink node through multi-hop. According to the method, the road network information can be effectively collected, and the data transmission delay can be reduced.