It refers to the structural form formed by connecting steel plate and hot tie, cold bend or welded profile through connecting piece, which can bear and transfer load.Steel structure system has the advantage of light deadweight, factory production, fast installation, short construction period, good seismic performance, investment recovery faster, less environmental pollution and other comprehensive advantages, compared with a reinforced concrete structure, more in the "high, big and light" three aspects of the development of unique advantages, worldwide, especially in developed countries and regions, the steel structure in the rational, widely used in the field of construction engineering.Steel structure industry is usually divided into light steel structure, high-rise steel structure, residential steel structure, space steel structure and bridge steel structure five subcategories.

Steel structure is widely used in various engineering construction, such as steel bridge, steel plant, steel gate, various large pipe containers, high-rise buildings and tower rail mechanism.