Abstract: This paper proposes a routing algorithm based on fish swarm optimization for vehicular Ad Hoc network (VANET) in urban road environment. In vehicular Ad Hoc networks, the high-speed movement of vehicles leads to frequent changes of network conditions and topology. This paper uses fish swarm optimization model to assist the search and find a new optimal relay node for vehicles to ensure the message transmission in VANET. This paper proposes the fish swarm routing (FSR) optimization algorithm, which has the advantages of fast convergence and high efficiency. Experimental results show that the proposed algorithm has lower transmission delay and higher packet delivery ratio compared to existing approaches.