As machining technology develops toward the unmanned and automated system, the need for chip-breaking control is considered increasingly important. In this paper, chip-breaking limit of 3-D complicated groove insert is proposed according to cutting experiments. The mathematical formulation of chip section profile coefficient is established through the analysis of influential effect of 3-D complicated groove on chip section profile. The chip-breaking model is developed to predict the critical feed rate and the critical depth of cut in machining based on analyzing the restricted effect of 3-D complicated groove on chips. Finally, a full experimental validation of the analytical model is presented for chip breaking when the workpiece is steel, 45. The testing results show the critical feed rate model and critical depth of cut model are reasonable and reliable.