Abstract: The related equipment of speed measuring and ranging system is the key equipment of train control system in urban rail transit. Through analyzing and researching on the design requirements and technical background of the speed measuring and ranging system of urban rail transit, a kind of hardware architecture of the system based on head and tail redundancy was designed to implement safety redundancy for on-board speed sensor of double end. Then the design scheme of the train speed measuring and ranging system using multi sensor fusion technology was put forward.