The cracking tendency of large-scale high-chromium cast iron impeller was large, and its casting production was a problem in slurry pump industry. The casting process of the largest high-Chromium cast iron impeller in China was presented in this paper. Through casting process design and alloy composition design, the produced impellers met the quality demands, such as no crack, surface smoothness and high hardness. Huazhu CAE was used to simulate the casting process and the parameters used in the simulation were introduced. The STL document used in Huazhu CAE was converted from the 3D molding of the casting process using the Solidwork software. The simulation result showed that the casting process was feasible. They have been successfully used in the dredge, New Sea lion.