The Z-type spring is a key part of the non-vibration air suspension. The non-vibration air suspension was developed long ago and widely used in developed countries. It has strong durability, provides a smooth ride, protects the vehicle body, and protects luggages from damage in truck. In this study, the structural strength of the Z-type spring was evaluated by computing the maximum displacement and the von Mises maximum stress results from applying the load condition based on the maximum weight of luggage in the rear space of a truck.