Keel is a kind of building material used to support modelling and fixing structure. It is widely used in hotels and terminal buildings. Passenger station, station, theatre, shopping mall, factory, office building, old building renovation, indoor decoration, roof and other places. Keel is the skeleton and base material of decoration, which is widely used. There are many kinds of keel, which can be divided into wood keel, light steel keel, aluminium alloy keel, steel keel and so on