The invention discloses a numerically controlled machine tool for saving part processing time, which comprises a tool storage box, a clamping box is fixedly installed on one side of the tool storage box, a first air cylinder is fixedly installed on the inner wall of the bottom of the clamping box, the second The top of the output shaft of a cylinder is fixedly installed with a horizontally placed placement plate, the placement plate is located above the first cylinder, the top of the placement plate is provided with a tool, and a second cylinder is fixedly installed on one side of the inner wall of the tool storage box. The cylinder is located above the placement plate, the output shaft of the second cylinder is fixedly connected with a push plate, and the push plate is in contact with one end of the tool, and the clamping box is provided with a mounting hole, and the inner wall of the mounting hole is fixedly installed with three Evenly spaced support columns. The invention realizes the automatic replacement of the cutter of the numerical control machine tool, facilitates the processing of the parts, saves time, and at the same time, through the stable clamping, the installation of the cutter is more reliable, the processing quality of the parts is guaranteed, the use is convenient, and it is easy to popularize.