The optimal design for the spring's parameters improves dynamic and static characteristics of truncated conical spiral compression spring. Owing to the non-linear vertical stiffness of the spring，improves the vehicle's dynamic performances under two loads of the light and the heavy，optimizes spring horizontal properties，and significantly reduces the locomotive vehicle displacement in the horizontal load. The strength and radial stability meet the design requirements. Loading application results show that truncated conical spiral compression springs can be used in railway locomotive vehicle.