The new requirements of the surface protection are presented with the development of the wooden-structure protection concept and the traditional method of the surface protection cannot adapt to that. As an international cooperation project, rehabilitation project of Huguang Assembly Hall in Chongqing attempts to improve the surface protection of traditional wooden-structure buildings scientifically and professionally by setting up a special project, laboratory analysis, tests on site, effective methods to different degrees of desquamation and diseases of the wooden-structure.