Abstract: With the help of SolidWorks software, the three-dimensional model of ductile iron QT500-7 fixed base was established. Its structural characteristics, process requirements and actual conditions were analyzed to initially design the casting process scheme, and the simulation of mold filling and solidification shrinkage was performed by using simulation software. The simulation results show that the filling process is stable and there is no insufficient pouring or cold separation, while there are shrinkage holes in the thick part of the fixed base. The casting process was adjusted by adding risers and cold iron. After optimization and simulation, the quality of the castings is significantly improved, and no defects in the castings. The optimized scheme can provide theoretical support for the actual casting process design of the fixed base.