The construction industry refers to the material production department in the national economy engaged in the survey, design, construction of construction and installation projects, as well as the maintenance activities of existing buildings. According to the national economic industry classification catalog, as one of the thirteen branches of the national economy, the construction industry is composed of the following three major categories: civil engineering construction industry; Line, pipeline and equipment installation industry, survey and design industry. The main function of the construction industry is to carry out construction and installation activities on various building materials and components, machinery and equipment, and to build productive and non productive fixed assets for the national economy. The development of the construction industry is closely related to the scale of fixed assets investment, which promotes and restricts each other.