Abstract: Taking the Siemens 840D sl five-axis CNC machine tool as an example, this paper expounds in detail the five-axis function parameter configuration method, the 3D probe debugging and calibration method, and the accurate calculation of the five axis transformation geometric vector based on the space standard sphere and the Siemens five-axis calibration cycle (cycle9960). Through the vector calibration of the five axis machine tool rotation axis, axis and other motion systems, the workpiece measurement error of the five-axis CNC machine tool is effectively reduced. At the same time, the working principle and execution process of 840D sl five-axis coordinate conversion and Siemens measurement cycle are also deeply studied. Based on the motion change law of tool axis vector in the machining process of Siemens 840D sl five-axis machine tool, a workpiece measurement method suitable for universal five axis machine tool is adopted, so as to realize automatic measurement of workpiece coordinate in the process of machining, shorten the auxiliary time of part processing, and improve the processing efficiency and accuracy.