In the process of turning high-temperature and high-strength steel, it is an effective method for chip breaking with complicated groove insert. In this paper, chip breaking mechanism is analyzed using the coated complicate groove insert for cutting high-temperature and high-strength steel. The model of chip curl radios is constructed though analyzing the effect of complicated groove insert on chip formation. The mathematical formulation of chip section profile coefficient is built through analyzing influential effect of complicated groove on chip section profile. The chip breaking model is developed according to chip-breaking criterion. Finally, a full experimental validation of the model is presented for chip breaking when the workpiece is high-temperature and high-strength steel, 2.25Cr-1Mo-0.25V. The tested results show the chip breaking model is reasonable, and the optimization cutting parameters are obtained.