This article is intended for proposing a solution to improvement,optimization and lightweight design of the heavy truck’s single-deck frame based on the causes to the fractured traditional double-deck frame assembly produced by SINOTRUCK WANGPAI MOTOR through the optimal design and improvement on the heavy truck‘s frame by finite element analysis of the structural stress and strain,which indicates that the optimized single-deck frame significantly improves in strength and rigidity and is lighter in weight that could satisfy the design requirements. The technology has been successfully applied to mass production of the current product line with good market response and favorable socioeconomic performance brought to the business.