Abstract: ProCAST software was used to calculate physical parameters of Ti-47Al-2W-0.5Si alloy, and a finite element model of TiAl based alloy blade casting prepared by metal-bottom pouring vacuum suction casting was established; The effects of mould temperature, pouring temperature and pouring velocity on solidification process of the alloy were simulated, and the optimized process parameters were obtained. At last, the experiment verification was carried out. The results show, with the increase of pouring temperature, the shrinkage reduced, and with the increases of pouring velocity, the shrinkage decreased first and increased. Increasing mould temperature was good for casting feeding. The optimized process parameters were pouring temperature of 1 620 ℃, pouring velocity of 1 m·s-1 and mould temperature of 20 ℃, and under the optimized parameters, the blade casting almost without shrinkage could be obtained. The simulated results were consistent with the experimental results, which verified the correctness of the proposed model.