This study presents a comprehensive approach to optimizing the sand casting process for Industrial Four-Way Valve Bodies through the integration of digital simulation and experimental validation. Unlike traditional methods that rely heavily on empirical experience, this research employs ProCAST software to simulate critical aspects of the casting process, such as metal flow, temperature distribution, and defect prediction. The simulation results were validated through practical experiments, leading to significant improvements in mold design and process efficiency. Key innovations include an optimized gating system and the strategic use of materials like FeCr50 and FeCr60 to balance cost and performance. The final castings exhibited superior quality, with defects such as shrinkage and cracks eliminated, and achieved an average hardness of 64 HRC. This approach not only enhances the production of Industrial Four-Way Valve Bodies but also offers a scalable solution for other complex sand casting applications. By bridging the gap between simulation and real-world implementation, the study contributes to advancing the competitiveness and sustainability of the Vietnamese sand casting industry.