Piston is the ‘heart’ of the automobile engine. It’s one of the key components of the engine and it’s working the hard condition which accelerated the piston wear and broken. A good design of the piston in this thesis is compared with existing piston to extend the Mean Time Between Maintenance. In order to achieve the deformation, thermal and stress distribution of the piston, ANASYS software is used to analyze the piston under the thermal loads and mechanical loads. The results are shown that the temperature distribution occurs on the top of the piston when the piston under the thermal load and the greatest stress occurs on the piston pin when the piston under the thermal-structure coupling. The temperature distribution is conformed to the facts, but the greatest stress is a bit large when coupling.