The work aims to design an innovative structure of reinforced honeycomb core. The shape of the new core layer in the hexagonal honeycomb cell was determined based on the bonding size of the plate. With the straight rib structure selected as the research object, out-plane bearing capacities of the innovative structure and common structure were compared. Based on the existing processing technology of the existing honeycomb core, the forming process and parameters of such honeycomb core were analyzed and researched. The new structure could realize bonding in plate state. When the bonding size in cell element was 0.625 times the size of side length of cell element, the straight rib structure could be formed in honeycomb core and distributed uniformly. The plateau stress of the innovative structure was 315.74% higher than that of the common structure. Besides, semi-automatic and fully automatic bonding processes were designed with respect to such structure. The innovative structure is scientific and stable, the bearing capacity is significantly improved, and the core bonding process changes little, which could provide a reference for the expansion of sandwich plate structure and forming process.