Abstract: As the speed of train is greatly increased, a series problems of air dynamics are raised, which will influence the safety of the train in motion, and passengers' and working staffs' safety at the station platform. Owing to the high speed, safety problem is of special importance. The safety particularity of the express train determines the particularity of the safety ensuring system of the express railway. The safety system of express railway is studied, in which the standard of withdrawal distance for person when the express train passing by, the safety supervision, and the ensuring system are emphatically discussed, and some suggestions are put forward.