Machine tool spindle gearbox

The utility model relates to a machine tool spindle gearbox. The machine tool spindle gearbox comprises a box body, an input shaft and an output shaft, wherein the input shaft is fixedly connected with a main input gear, and the output shaft is fixedly connected with a main output gear. Each shifting group comprises a clutch, a hollow shaft and a solid shaft, wherein the upper portion of the hollow shaft and the lower half edge of the clutch are fixed, a hollow shaft gear meshed with the main input gear is fixedly arranged at the lower portion of the hollow shaft, the upper portion of the solid shaft is fixedly connected with the upper half edge of the clutch, a solid shaft gear meshed with the main input gear is arranged at the lower portion of the solid shaft, and the solid shaft is connected inside the hollow shaft in a sleeved mode through a bearing, and the hollow shaft and the solid shaft are coaxial. The machine tool spindle gearbox reinforces rigidity of a transmission chain, prolongs the service life of the gears and supporting bearings on the shafts, reduces the volume of a cavity inside the gearbox, is more stable, avoids the design of an inner sliding spline and an outer sliding spline inside a transmission spindle gearbox, reduces machining difficulty of the shaft gears, and improves reliability of the shaft gears.