This paper introduces the composition and working principle of the vehicle information detection system which uses ARM and DSP processor as hardware architecture. ARM has abundant of network interfaces, it can easily implement network, DSP can provide powerful computing capabilities, to achieve complex operations. This paper combination both of the advantage to formation the vehicle information detection system. This design combination practical situation, it based on fully using current resources, and designed a practical circuit and related program which according with the requirements, it have an important significance of theory and pratical.