Movable auxiliary air pipe

The utility model relates to a movable auxiliary air pipe. The movable auxiliary air pipe comprises an upper pipeline, n intermediate pipelines and a lower pipeline, the upper pipeline is composed of four top side right angle unit pieces and top side unit pieces clamped between each two top side right angle unit pieces in a splicing mode, and the section of the upper pipeline is square; the n intermediate pipelines are clamped below the upper pipeline in sequence in an aligning mode; the lower pipeline is clamped below the lowest intermediate pipeline in an aligning mode; n is a natural number, and the length of the auxiliary air pipe is larger than or equal to two times of the length of each side of the section thereof. By means of the movable auxiliary air pipe, the number of the unit pieces can be changed according to different sizes of tested air holes so as to enable the section size of the auxiliary air pipe to match with the sizes of different tested air holes, and moreover, the length of the auxiliary