Abstract: For the problem that the deviation caused by tool wear cannot be accurately and synchronously detected when batch parts with the same structure are processed by multi-station combined clamping and CNC machining, the CMM module of UG software is explored and applied to perform online detection of the batch assembly clamping process of parts. The detection motion paths of the probe are planned, several geometric elements of the workpiece are inspected, the system inspection macro programs are compiled and called, and the condition transfer functions of macro program are used to quickly detect the deviations caused by tool wear. The tool compensation parameters are adjusted and the deviations for the parts clamped in different workpiece coordinate systems of CNC machine tools(G54~G59) are corrected. The results show that the application of online inspection technology can effectively expand the functions of CNC machine tools and significantly improve the processing quality and efficiency of mass-produced parts.