Based on the theoretic analysis and experiments on milling the carbon structural 45 steel with the flat rake milling insert and the waved-edge milling insert with complex 3D grooves which is developed by HarBin University of Science and Technology, we have studied on the impact disrepair mathematic model and groove optimization. On the basis of the milling force mathematic model and force density function of the waved-edge milling insert with complex 3D grooves the author built, we have the finite element analysis and blurry synthetical judgement of the 3D stress field, and forecast that the anti-impact disrepair capability of the waved-edge milling insert is choiceness. We find out the difference of the impact disrepair invalidation types between different grooves milling inserts by the experiments. Based on the plentiful and systemic impact disrepair experiments, as the emphasis in this paper, we build the impact disrepair life cumulating distribution function mathematic model by the mathematics statistic method and have contrast analysis of the impact disrepair average lives between the two types of milling inserts, and prove that the anti-impact disrepair capability of the waved-edge milling insert is choiceness. All these studies provide the theoretic and experimental basis for solving the cutter disrepair which is the key problem in the automatization production and groove optimization.