NUMERICAL CONTROL DEVICE AND MACHINING METHOD

A numerical control device includes: a memory storing in advance angular difference information between each of first cutting shafts formed for an upper tool post and a second cutting shaft of a lower tool post and a machining program including a movement command for the upper tool post to move an imaginary shaft, which moves along the same line as the second cutting shaft and performs cutting from a direction opposite to the second cutting shaft with respect to the main shaft; a shaft-command distribution processing unit distributing the movement command to move the imaginary shaft to the first cutting shaft components based on the angular difference information; and a shaft-synchronization processing unit driving the first cutting shafts based on the movement command distributed to the first cutting shaft components and driving the second cutting shaft by the movement amount same as that in the direction of the imaginary shaft.