The automatic tool change system is abbreviated as ATC, ATC spindle which is an important part of the machining center. It realizes the tool change requirement of continuous machining between parts processes, that is, after each process is completed, the new tool used in the next process is automatically changed to the spindle, thereby It ensures the process characteristics of the machining center process concentration, and the exchange of tools is generally completed through the coordinated actions of the manipulator, the tool magazine and the machine tool spindle.