Steel structures are widely used in high-rise buildings, large factories, long-span space structures, light steel structures, and residential buildings. In highway and railway bridges, thermal power main plants and boiler steel frames, transmission and transformation towers, radio and television communication towers, offshore oil platforms, nuclear power plants, wind power generation, water conservancy construction, underground foundation steel sheet piles, etc. Urban construction requires a large number of steel structures, such as subways, urban light railways, overpasses, environmentally friendly buildings, public facilities, temporary buildings, etc. In addition, steel structures are also widely used in small lightweight structures such as supermarket shelves, scaffolding, square sketches, sculptures and temporary exhibition halls.