Abstract: Because of its complex shape and thin wall thickness, the large titanium alloy base has the characteristics of difficult forming and easy deformation. The forming method of machined graphite mold was studied. Through the design of rain-dense distribution and multilayer gating system, reasonable melting and pouring parameters were set, and the castings were annealed. The final castings are well formed, and the internal and external quality and properties of the castings meet the use requirements.