The invention relates to the technical field of accessory devices for workpiece calcination, in particular to a calcinator for spinning workpieces. The height of a work box of the calcinator can be adjusted according to the demands of workers to improve the adaptability of the calcinator, and therefore more convenience can be provided for fixation of irregular workpieces, and the use reliability of the calcinator is improved; the location of a placing shelf can be adjusted according to the workpiece demands, so that use boundedness of the calcinator is decreased; the calcinator includes the work box, the placing shelf and four groups of supports, the inner side wall of the work box is provided with multiple groups of U-shaped heaters; all groups of the supports comprise inserting columns, inserting pipes, left limiting plates, left connecting rods, left sleeving springs, left connecting plates, left limiting blocks, right limiting plates, right connecting rods, right sleeving springs, right connecting plates and right limiting blocks, and the left and right side walls of each inserting pipe are provided with a left through hole and a right through hole respectively; the calcinator further comprises two groups of fixing plates, two groups of fixing springs and two groups of fixing blocks respectively. The side wall of the inner bottom of the work box is provided with a sliding groove in the front-back direction and a sliding plate.