A multi-purpose precision machine tool is provided, which has main structures including a machine tool body, and a first workpiece fixing mechanism, a second workpiece fixing mechanism, and a tool mechanism provided on the machine tool body. The first workpiece fixing mechanism and the second workpiece fixing mechanism respectively include an internally expanding clamp and a soft-jaw chuck for clamping a workpiece, so as to not only drive the workpiece to rotate, and but also drive the workpiece to perform horizontal and vertical linear displacement. Therefore, the internally expanding clamp can first clamp the workpiece to machine one end of the workpiece, and then the soft-jaw chuck clamps the other end of the workpiece to machine the other end of the workpiece.