The light steel structure building: the roof, wall and floor board are composed of galvanized sheet cold rolled into light steel keel. The middle is filled with heat preservation and sound insulation materials, and the inner and outer walls are covered by the substrate and decorative panel. All materials are prefabricated in the factory, without dust pollution, and the installation is quick. All room types can be designed according to customer needs. The cost of light steel buildings is 30% or more lower than that of traditional buildings. And a wide range of applications, such as: villas, hotels, apartments, warehouses, office buildings, teaching and library buildings, resorts, street commercial buildings, small hospitals and gymnasium, etc. building. The construction process is simple. Environmental protection, earthquake, wind, fire, moisture, heat preservation, insect, light weight, easy to carry and build. Therefore, it can fully meet the residential and commercial needs of different classes in different countries.