Large complex rudder framework titanium alloy casting method

The invention provides a large complex rudder framework titanium alloy casting method, which comprises the following steps of: designing a bottom pouring type pouring system according to the structural characteristics of a rudder framework titanium alloy casting to be formed, penetrating a sprue from the top of the bottom pouring type pouring system to the bottom of the bottom pouring type pouringsystem, generating a graphite mold in a software differencing mode according to the bottom pouring type pouring system, enabling the graphite mold to enter a degassing furnace for degassing at normaltemperature, the vacuum degree of the degassing furnace being less than 3 Pa, assembling and combining the split graphite mold subjected to degassing, and putting the assembled graphite mold into a titanium alloy skull furnace, conducting vacuum pumping to melt a titanium alloy ingot, conducting casting forming, and generating a formed rudder framework titanium alloy casting. The method can meetthe production requirements