Abstract: With the development of the automation of CNC machine, new requirements are put forward for the automation of all parts of the machine. Tailstock is an important part of CNC lathe. Its precision directly affects the quality of the workpiece. The device based on programmable tailstock will realize the automatic control of tailstock. In this paper, a new device of programmable tailstock has been introduced according to the new requirements, the purpose is to improve the automation degree of the CNC machine and efficiency as well as accuracy, and reduce the labor intensity of the operator.