VANET is a special application of traditional MANET in traffic. The research with the use of routing protocols of MANETs to adapt VANETs has become a popular research direction, while few papers focus on the performance analysis of routing protocols in traffic scenarios and implementation of VANET terminals. Therefore, this paper compares the performance of AODV, DSR, OLSR and AODVUU in VANET simulation environment, using network simulation software and traffic simulation software. Together with simulation results, AODVUU is chosen and modified for multi-path AODVUU aiming at reducing the packet loss rate and the routing overhead. Finally, an embedded vehicle terminal is designed and implemented based on the above and the actual transmission performance is evaluated on an ad-hoc network with three nodes.