Abstract: This article provides a detailed introduction to the development and optimization process of casting technology for high-speed train gearboxes. Through in-depth analysis of product structure, requirements, and important parts, a scientific and reasonable overall casting process plan was developed, and process optimization was carried out using simulation software. A series of effective measures have been taken to address the porosity and shrinkage defects that occur during the production process. The practical results show that the optimized process not only significantly improves the yield of the gearbox, but also makes its quality fully meet the technical requirements of the product.