Abstract: According to the practical conditions of 65 t ladle at Tangshan Iron & Steel Corp.,numerical simulation of flow field,death zone and mixing time of the ladle has been carried out by Fluent software.The results were verified with the cold model simulation,which provided theoretical and experimental basis for the optimization of constructional and technical parameters of bottom blowing.Higher velocity zone of the molten steel concentrated at the high-speed gas-liquid jet area and the top of the ladle,while the death zone located at the bottom of the ladle.Under the condition of 100 L/min bottom blowing,the volume ratio of the death zone was small as the intersection angle and the center distance of bottom blowing were 180° and 0.6R,respectively.Under this constructional condition,the volume ratio of death zone and the mixing time were declined with the increasing of the bottom blowing flow.The changing tendency of mixing time was verified by the cold model experiment.The mixing time obtained by numerical simulation was consistent with that determined by the cold simulation,which proved the reliability of the numerical simulation.