The focus of this paper is on vacuum investment casting technology for titanium alloy castings, particularly those with thin-walled narrow grooves and deep blind cavity structures. Owing to the high chemical reactivity of titanium alloys, which are susceptible to reactions with various atmospheric components, stringent requirements are placed on the selection and drying process of mold shell materials. However, limited drying conditions in narrow, deep blind cavity molds often lead to defects such as cold shuts, misruns, and gas porosity during pouring, causing the castings to fall short of service standards. To address this issue, casting simulation technology was utilized to analyse metal-filling behavior precisely and ensure the sequential filling of thin-walled regions. Additionally, the filling path and gas escape channels in the investment casting process were optimized, effectively resolving issues related to dense pores and achieving stable mass production of complex titanium alloy castings.