A numerical control device which controls a feed axis of a machine tool (10) has a storage unit (92) which divides a range of movement of the feed axis into a plurality of regions and stores a plurality of control parameters corresponding to said divided plurality of regions in advance, a position detection unit which detects a position of a feed axis at the time of machining a workpiece, a parameter selection unit (90) which reads out control parameters corresponding to a divided region to which the detected feed axis position at the time of machining a workpiece belongs, and a servo control unit (52) which controls the feed axis using said read control parameters. Due to this, it is possible to provide a numerical control method of a machine tool which realizes stable machining precision without regard as to the feed axis position and a numerical control device which conducts that method.