Abstract: Based on the structural characteristics and casting requirements of high-pressure steam chamber steel castings, a preliminary scheme of sand casting process for steel castings was designed, and the simulation of filling and solidification shrinkage was carried out by using ProCAST software. The simulated result show that filling is stable and no insufficient pouring occurred. However, large volume shrinkage holes are appeared in the bottom thick part and top boss of the steam chamber, and dispersed shrinkage defects are produced in the castings. Based on the simulation results, the riser and cold iron are added to the defect part, and its simulation results show that the optimized designed casting process is good without shrinkage hole defects.