Abstract: The 1215 free cutting steel is successfully developed by 120 t converter-120 t LF-180 mm x 180 mm billet casting high-speed wire rolling flowsheet. The key control point is converter tapping steel C ;0.05% , converter end temperature 1630 ~1660 °C , refining free oxygen control target 50 x 10 ^-6 ~ 55 X 10 ^-6, and binary slag basicity 2.5 ~ 3.0. The composition design is 0.05% 〜0.07% C, 1.20% 〜1.35% Mn, and 0. 340% 〜0. 360% S. On this process conditions ,the morphology and content of sulfide in steel are controlled reasonably. The Mn/S is beneficial to the rolling and improving cutting performance of free cutting steel. The superheat of molten steel is controlled within 25 〜40℃ and the casting speed is 1.2 m/min. It shows that accurately predicting the end-point oxygen content to determine the amount of deoxidizer added, and reasonable control of the oxygen content of different processes are the key to achieve stable quality control of wire products.