The utility model discloses a length screw thread and compound regulation formula member of jack that dish knot formula steel pipe support used, the connecting pipe that is hollow structure including inside, be provided with the internal thread on the inside pipe wall of connecting pipe, be provided with a plurality of first patchholes that link up the pipe shaft on the connecting pipe, still including 2 regulation poles, it has the buckle elbow to adjust head end swing joint on the pole, 1 be provided with on the root regulation pole with first patchhole complex second patchhole, 1 piece other regulation pole is provided with the external screw thread on one's body, after the regulation pole that is provided with the second patchhole stretches into to the connecting pipe in, pass through the bolt that will to adjust the pole behind 2 patchholes fixed. The accessible bolt will be adjusted the pole and be fixed in inserting in the hole of different positions on the connecting pipe to realize the regulation on a large scale of length, and length be need finely tune the time, twist or back -out have the external screw thread the regulation pole can, can both block well in the breach of chuck no matter pole rotation to optional position, its buckle elbow is adjusted to the buckle elbow of activity.