For a vehicle engine, the piston is the essential part that bears heavy mechanical and thermal loads, therefor; it has very many influences on the reliability and durability of an engine. So the piston greatly hinders the increase of power of an engine. For high-powered heavy loaded vehicle engines, using the LHR piston is an effective way to enhance the piston's performance of enduring thermal loads and reducing heat rejection. This paper presents the study of the LHR piston and its structure. The three-dimensional FEA of the piston was offered, its mechanical and thermal loads were calculated and a large amount of useful data was obtained.