Abstract: A bending tube including a plurality of structural units (100). Each of the structural units (100) includes a first connecting pipe and a second connecting pipe. One end of the first connecting pipe is provided with a slot and a T-shaped structure, a clamping block and a limiting slot are provided on one end of the second connecting pipe, a first limiting structure (7) is provided on both sides of one end of the limiting slot, and the other end of the limiting slot is provided with a second limiting structure (8); the clamping block and the T-shaped structure are located in the limiting slot, two flanks are provided on the original pin to form a T-shaped structure (6), and the T-shaped structure makes it difficult to disengage the pin, thereby increasing the strength of the bending tube in the direction perpendicular to the bend.