Abstract: A headstock structure of computer numerical control milling and boring machine tool comprising a spindle, a conducting slip ring, a rotating plate, a mobile unit, two balancing units, a driving unit, and a cutter locking unit; the conducting slip ring being sleeved on a top end of the spindle; the rotating plate being rotated in horizontal direction under the drive of the spindle; the mobile being rotated in horizontal direction together with the rotating plate; the two balancing units being located on the rotating plate; the driving unit being configured to drive the mobile unit to perform horizontal radial movement; the cutter locking unit being configured to lock the cutter, so that the headstock structure can rotate and move up and down, and can perform horizontal radial motion.