Abstract: The paper proposes a new design method to make the liquid-cooled chassis has better performance in strength, stiffness, cooling capacity, maintainability and so on. A new liquid-cooled chassis with interconnected 3D liquid channel is designed by material and technique selection, cold-plate dimensional tolerances calculation and configuration, structural & thermal design for the liquid channel, and ergonomical design. By a series of simulation and test verification, the chassis could meet the requirements of strength, stiffness and cooling, and also has good maintainability. The new design method of the liquid-cooled chassis enlarges the application range of the chassis, and enhances the versatility of airborne electronic equipment.