Abstract: This paper targets the Siemens 840D sl SINUMERIK Operate as the system application framework, and based on the Trace Service data acquisition function, a five-axis linkage accuracy evaluation module for CNC machine tools is developed, which targets the trajectory of S part as the object. Based on data requirements of the trajectory of the S part during operation, this paper analyzes the core principle of the Trace Service data acquisition mechanism, sorts the data acquisition process and designs the sub-module of the coordinate axis data acquisition through the data requirements of the trajectory of the S part during operation, analyzes and extracts the results of the data acquisition to convert the axis coordinates to tool tip points, and completes the display of graph and index of the contour error with the graphical-digital method, so as to achieve the evaluation of the five-axis linkage accuracy of the CNC machine tool. This module uses the excellent linkage accuracy evaluation performance of S part, integrates efficient data acquisition and contour evaluation display, avoids the fussy process of traditional acquisition and evaluation, and effectively improves the economy and efficiency of the evaluation.