Abstract: Abstract：[Objectives] Composite material design and structural design are separated in the "double track" state. Aiming at improving the ultimate strength of marine composite structure, it is proposed the integrated design method of composite material. [Methods] Based on the multi-scale method, the correlation between meso-scale material and macro-scale structure is established, and the influence of meso-scale parameters on the ultimate strength of macro-scale stiffened panels and the difference of mechanical properties between intra-layer and inter-layer hybrid of carbon and glass fibers is explored. Through comparison, the better structural form is obtained. [Results] The established the micro-meso-macro mechanical analysis method can improve the ultimate strength of macro-scale stiffened panels by enhancing the meso-scale parameters of composite materials. By adjusting the spacing and cross-sectional area of TC33 yarn, the cross-sectional area of WR yarn and the mixing mode, the designed composite top-hat stiffened structure has better ultimate strength. [Conclusions] The integrated design of material and structure can be realized under the premise of satisfying the requirements of the rules through multi-scheme comparison and optimization, which provides theoretical guidance and technical support for the novel design of naval ships.