In milling process, tool wear has important influence on product machining quality. A measuring method for tool wear of ball-end cutter is proposed in order to predict effectively tool wear. The measuring method maps tool wear shape on a block of metal material by milling hole mode after finishing each milling experiment. These formed holes are measured on CMM (coordinate measure machine) by using the planned measuring method. The measuring process is established to attain tool wear of ball-end cutter. The experiments results show that the proposed measuring method can effectively attain tool wear to provide a foundation for tool wear modeling and monitoring.