Aluminium profile is widely used in rail transit, which can be used to make car body such as roof, side wall, floor, etc., and can also be used to make small accessories such as: luggage rack, door, pedal, water tank, etc. The use of aluminium instead of steel material can greatly reduce the weight of the train, save energy and reduce emissions. Meanwhile, due to the weight reduction, it is easier to control and more stable to run the train in telling operation, turning, undulating and other harsh environments. Typically, high-speed trains that travel at speeds of more than 250 kilometers per hour are made of aluminium.