The filling process and solidification of TiAl based alloy blade by suction casting was studied via numerical simulation. The shrinkage defect of TiAl based alloy blade casting was predicted using FEM software ProCAST. The results indicate the cold shut will be decreased with the increase of graphite suction opening diameter and the pouring temperature. With the decrease of the coefficient of heat transfer, the cold shut is reduced. The TiAl blades are obtained by this method. The simulated result tallies well with the actual cast experiment, and lays down a foundation for improving the cast technology of the TiAl based alloy casting.