It explores one totally new design method of space layout for heavy truck interior layout. Through analyzing the heavy truck interior space， it introduced the design for small spaces into it. According to the similarity between them and the uniqueness of the former， combined with ergonomics and design psychology， it tried to research the heavy truck as a small interior space. Under the precondition of the comfort and security，it put forward a more humanizing，more corresponding the man-machine relationship of heavy truck interior designing method.