The automatic tool changer is divided into ATC linear tool changer and ATC carousel tool changer. The standard configuration is an ISO 30 tool holder, which can be with 20mm max.diameter tools. The ATC linear tool changer is fixed at the tail of the machine. Each time the tool is changed, it is necessary to return to the tail from the working area to change the tool, perform tool setting and zeroing, and then perform work. Compared with manual tool change, it is more convenient and more efficient. Compared with ATC carousel tool changer, the price is cheaper; The ATC carousel tool changer is fixed on the side of the gantry and is always on the same horizontal line as the spindle, and the tool change does not require tool setting and zeroing, which is more efficient than the linear tool changer.