The invention relates to a machine tool for pin shaft workpiece machining. The machine tool comprises a mounting table body. A workpiece clamping and rotating mechanism is arranged on the mounting table body, and a machining cutter mechanism is arranged on the front side of the workpiece clamping and rotating mechanism. A workpiece input mechanism is arranged on the portion, on one side of the workpiece clamping and rotating mechanism, of the mounting table body, and a workpiece discharging mechanism is arranged on the portion, on the other side of the workpiece clamping and rotating mechanism, of the mounting table body. The machine tool has the functions of surface cutting machining and end chamfering and drilling machining of pin shaft workpieces, a previous machining manner of manuallyreplacing cutter frequently is replaced, equipment input is reduced, meanwhile, automatic feeding and discharging of the pin shaft workpieces are achieved, and a previous machining manner of manuallyassisting in feeding and discharging is replaced; and the workpiece machining efficiency is improved, and the quality and precision of pin shaft machining are ensured.