How to select the optimal semi-trailer suspension system is a crucial decision for fleet managers and property operators, directly affecting operational cost control, cargo transportation safety, and vehicle lifespan. The selection disputes within the industry mainly focus on three core technical solutions: traditional mechanical suspension, advanced air suspension, and dedicated single-point suspension. This article will deeply analyze the core differences in durability, driving smoothness, and cost-effectiveness among these three types of suspensions, and clarifying these differences is the key prerequisite for improving vehicle fuel efficiency, ensuring cargo integrity, and enhancing transportation safety.