In view of the problems of low automation and high labor intensity in the turning process of centerless lathes, the technical contradiction of centerless lathe was analyzed by using TRIZ innovation theory, the invention principle was found out in the contradiction matrix to determine the improvement scheme of centerless lathe. A kind of centerless lathe with concentric double axis structure and thread driven tool feed was designed, the tool feed and retreat were realized through the speed difference between the two axes; the cylinder axis and the cone surface were turned,and the machining range of the centerless lathe was expanded. The simulation of centerless lathe turning was carried out by using Deform software, and the comparison of simulation value and theoretical value of turning load was carried out. The results show that the error of simulation value and theoretical value is within the acceptable range, which verifies the rationality of careless lathe design and the feasibility of turning machining.