Finish machining die and method for titanium alloy thin-walled shell casting blank

The invention provides a finish machining die and method for a titanium alloy thin-walled shell casting blank. The finish machining die is characterized in that the titanium alloy thin-walled shell casting blank is externally coated with an external casting mold and internally contains an internal casting mold. A fusible alloy is externally cast on the outer surface of the titanium alloy thin-walled shell casting blank, so that the outer surface of a titanium alloy thin-walled shell is thickened, and the thin wall cannot deform during cutting of the inner surface. Similarly, the fusible alloy is internally cast on the inner surface of the titanium alloy thin-walled shell casting blank, so that the inner surface of the titanium alloy thin-walled shell is thickened, and the thin wall cannot deform during cutting of the outer surface. By adoption of the finish machining die and method, the rigidity and the strength of parts can be effectively improved, the working procedures are reasonably arranged, the working efficiency is high, the machining cost is low, and not only can the problem of machining deformation of titanium alloy thin-walled shell parts be solved, but also the machining precision and the surface quality of the parts are greatly improved.