The invention relates to a variable cross-section composite material battery shell and a fabrication process thereof. The battery shell comprises a battery shell outer plate and a battery shell cover,wherein the battery shell outer plate is made of composite material and comprises a variable cross-section panel, the battery shell outer plate refers to a plate forming an outer surface of the battery shell, the variable cross-section panel pane refers to that the panel thicknesses of the battery shell outer plate at different positions in a height direction are different, and the situation thatthe panel thicknesses of the battery shell outer plate at different positions in the height direction are different is achieved by laying different layers of composite materials on regions with different heights of the battery shell outer plate. The bionic battery shell comprising the variable cross-section panel is combined, and the mechanical property of the battery shell is improved by a variable cross-section design and a layer laying design of the battery shell panel under the conditions of no high cost and no addition of an auxiliary reinforcement structure.