Abstract: According to the design characteristics of the roll used as one of the piercing tools, the design principle for the CTProll parameters is systematically discussed here in the paper, and the calculation formula for the major parameters and the issues as need to be focused on during the design process are analyzed.The analysis leads to such a conclusion as follows.Scientific and reasonable design of the CTProll will minimize the reduction amount without any negative effect on the bite, which is very helpful for the piercing step;moreover rolling-caused defects will also be reduced;particularly when producing steels which are normally rather hard to be managed, the said roll shows obvious advantages.Generally speaking, the properly-designed cone type piercer(CTP)will bring about such advantages as better product quality, lower energy consumption for rolling and lower tools consumption as well.