The invention relates to the technical field of artificial fibers, and discloses a length-adjustable automatic centering artificial fiber winding roller positioning device. The device comprises a base, wherein a supporting plate is movably connected to the top of the base, a driving wheel is fixedly connected to the bottom of the supporting plate, a supporting column is fixedly connected to the top of the supporting plate, an adjusting rod is movably connected into the supporting column, a worm is fixedly connected to the outer portion of the adjusting rod, and a fixed gear is connected to theouter portion of the worm in an engaged mode. Through cooperative use of the worm, a fixed gear, a fixed sliding block and a positioning plate, the effect of clamping a winding roller is achieved, the stability of the winding roller is effectively guaranteed, the winding rollers with different diameters can be conveniently fixed, the use range of the device is effectively enlarged, meanwhile, theeffect of automatically determining the axis of the winding roller is achieved, and the axis of the winding roller and the rotating axis of the supporting plate are collinear, so that the rotating stability of the winding roller is effectively guaranteed, and winding shaking is effectively avoided.