Recently, researches on light weight of vehicles have been actively carried out to reduce fuel consumption. Researchers have generally attempted to replace metal materials with composites, but these materials do not meet the required strength and rigidity of the vehicle and require a variety of design approaches. In this paper, deck assembly of truck was compared and compared with assembly using existing floor as Apitong, and it was verified by structural analysis and modal analysis. To do this, we measured the mechanical properties of the material through tests and evaluated the safety of the Deck Assembly through maximum equivalent stress, total deformation, and safety factor values. In addition, the fit of the hybrid deck assembly structure was evaluated by measuring the approximation of the analysis by single component assembly test.