Automation and intelligence have become the primary trends in the design of investment casting processes. However, the design of gating and riser systems still lacks precise quantitative evaluation criteria. Numerical simulation plays a significant role in quantitatively evaluating current processes and making targeted improvements, but its limitations lie in the inability to dynamically reflect the formation outcomes of castings under varying process conditions, making real-time adjustments to gating and riser designs challenging. In this study, an automated design model for gating and riser systems based on integrated parametric 3D modeling-simulation framework is proposed, which enhances the flexibility and usability of evaluating the casting process by simulation. Firstly, geometric feature extraction technology is employed to obtain the geometric information of the target casting. Based on this information, an automated design framework for gating and riser systems is established, incorporating multiple structural parameters for real-time process control. Subsequently, the simulation results for various structural parameters are analyzed, and the influence of these parameters on casting formation is thoroughly investigated. Finally, the optimal design scheme is generated and validated through experimental verification. Simulation analysis and experimental results show that using a larger gate neck (24 mm in side length) and external risers promotes a more uniform temperature distribution and a more stable flow state, effectively eliminating shrinkage cavities and enhancing process yield by 15%.