This paper proposes a trailing-edge morphing wing design method based on a series four-bar linkage mechanism, The method adopts a joint-type structure, optimizes rib segmentation and downward deflection angles, employs a series four-bar linkage mechanism to simplify the driving system design, and achieves precise control of multi-degree-of-freedom dynamic coupling motion. The article elaborates on key steps, including rib segmentation and deflection angle optimization, series four-bar linkage mechanism design, and functional deformation verification using a 3D-printed wing prototype. Experimental results demonstrate that the proposed design can achieve the desired airfoil shape variation, providing a novel approach for morphing wing trailing-edge design.