The Underwater Glider is a novel Autonomous Underwater Vehicle for ocean monitoring. ANSYS based optimization technology is utilized for lightweight design and research of underwater gliders. The numerical 3D model of the shell is constructed and the structural strength is analyzed. A modified design is introduced and then is optimized by ANSYS optimal process. The optimal lightweight structure is fully evaluated and proved to be successful. This design will improve the glider’s performance and the pressure hull strength, at the same time, it will reduce the weight and cost of the glider. In addition, this approach may provide a new guidance for further hull design of the underwater glider.