Infinite sliding rail capable of realizing extension at any length

The invention brings forward a sliding rail structure capable of realizing extension at any length, i.e., a multi-section infinite sliding rail structure which comprises a layer of outer slide rail, a plurality of layers of intermediate slide rail and a layer of inner slide rail. According to the invention, extension of a sliding rail at any length can be realized through selection of different layers of the intermediate slide rail according to actual conditions; since the width of each layer of slide rail is large and space among every layer is great, a variety of traps can be designed, which enables slide rails to carry out a variety of specific additional motion during extending or retracting, thereby satisfying needs of some special purposes.