The utility model relates to a coaster unable adjustment base with adjustable height, this unable adjustment base include the insulator yoke plate, carry line yoke plate and base, open on the top of insulator yoke plate has the yoke plate mounting hole, carrying the line yoke plate and including connecting plate and mounting panel, the top of connecting plate is connected with the bottom surface of mounting panel respectively, and the connecting plate is opened there is the yoke plate fixed orifices, through bolt fixed connection between yoke plate fixed orifices and the yoke plate mounting hole, opening of mounting panel has first pedestal mounting hole, the base includes bottom plate and height control board, the welding of height control board is on the bottom plate, the fixed plate is opened there is second pedestal mounting hole, bolted connection is passed through with second pedestal mounting hole in first pedestal mounting hole, the height control board is opened has a plurality of string height control holes of that are used for breaking out. The utility model discloses can fix on carrying the line yoke plate, select required height control hole to break out and hang, provide the highly suitable stable point of hanging for the operation coaster.