Multi-position expansion support

A multi-shift retractable pillar relates to rough hardware fittings, which comprises a bottom cut (1) and a slide bar (2) which can slide right and left in the bottom cut (1); the underside of the left part of the bottom cut (1) is provided with a left ear base (3), and the top surface of the right part of the slide bar (2) is provided with a right ear base (4). The multi-shift expansion pillar is characterized in that the top surface of the left part of the bottom cut (1) is provided with a jacking block (5) and the top surface of the right part is provided with a bottom cut blocking position (14), the underside of the left part of the slide bar (2) is provided with a link stopper (6) with a shifting fork (9), the shifting fork (9) is rotatably connected with the slide bar (2), the link stopper (6) is internally provided with a reed (8) matched with the shifting fork, the lateral surface of the bottom cut (1) is provided a shift hole (7) matched with the shifting fork (9), and the lateral surface of the slid