Abstract: The transformation process of filling and solidification of cobalt-chromium-nickel alloy in vacuum casting was studied by using the ProCAST software calculation and experiment. The temperature field and cooling velocity rules of cobalt-chromium-nickel alloy casting were analyzed. The experimental results were analyzed by using the cellular dendrite growth theory. The results show that the temperature distribution and cooling velocity of the alloy casting are well fitted by using the stepped casting. With the decrease of the casting thickness and the increase of the cooling rate, the overcooling degree and the cellular growth rate increase, and the tip radius and the spacing of cellular dendrite decrease.