Abstract: Casting process of a HT300 gray cast iron slide rail worktable was designed. Two different pouring schemes were designed and alkaline phenolic resin sand moulding was used. Solidworks and ProCAST softwares were used to carry out three-dimensional modeling, filling simulation and solidification simulation of casting process, respectively. The location of shrinkage cavity and porosity in real castings were simulated. Process optimization was carried out by changing process parameters, riser shape and position, and gating system. According to the simulation results of casting process, the design scheme of the casting and feeding system was selected, which was stable in filling and conducive to the elimination of defects such as shrinkage cavity and porosity. Finally, a reasonable worktable casting process scheme was obtained.