Aimed at the deficiency existed in the damper system of electrically-propelled vehicle and utilizing the characteristics of smoothness of hydraulic and pneumatic shock absorption a kind of mixed hydro-pneumatic pressure damper structure was designed. By way of carrying out the random vibration test in the laboratory on the being designed damper structure it was discovered that the shock absorption effect of the being designed damper was evidently better than the spring typed damper now existed, thus verified the feasibility and validity of this design.