compared with traditional, lightweight materials, the composite materials of cnt fiber are light in weight, as well as high in strength and modulus. they can be used as the lightweight and environmentally friendly materials of rail transportation. in the railway traffic equipment, the composite materials of cnt fiber can not only be used in the interior structures and equipment such as the skirt plate, air guide sleeve, interior decoration and apparatus, but also the bearing structures, such as the car body and framework, etc. the railway traffic equipment made of cnt fiber composite materials can decrease the weight by 13% and save energy by over 15%.