Pipe fitting telescopic structure

A pipe fitting telescopic structure relates to the technical field of telescopic structures and comprises an outer pipe provided with a telescopic space in a penetrating mode and an inner pipe arranged in the telescopic space, and the inner pipe can slide in the telescopic space of the outer pipe in the length direction of the outer pipe to drive the lower portion of the inner pipe to stretch out or retract from an opening in the lower end of the outer pipe. An expansion assembly is arranged at the upper end of the inner pipe, the inner pipe is rotated to drive the expansion assembly to expand, the expansion assembly is connected with the inner wall of the outer pipe in an interference fit mode after being expanded, and therefore the extending length of the inner pipe is fixed. Especially, by means of the structure that the telescopic length is fixed through the expansion assembly, the problems existing in the prior art are solved, the service life is long, telescopic positioning is stable, the telescopic len