A method and apparatus for preheating a bulb tube of medical equipment is provided. The method includes: selecting a scanning condition which satisfies an equipment calibration condition, as a preheating condition for the bulb tube, from scanning conditions used by the medical equipment; selecting a new preheating condition if an accumulated thermal capacity according to selected preheating conditions is smaller than a target thermal capacity, until the accumulated thermal capacity reaches the target thermal capacity, wherein the accumulated thermal capacity indicates a sum of a thermal capacity estimated to be generated when the bulb tube is preheated according to the selected preheating conditions, and the target thermal capacity indicates a thermal capacity required to complete the preheating of the bulb tube; preheating the bulb tube according to selected preheating conditions and executing an equipment calibration corresponding to each of the preheating conditions during the bulb tube preheating.