A numerical model was established using the finite volume method to establish a corresponding relationship between the simulated temperature with flow fields and the actual solidification structure of the ingot. The grain growth direction and grain morphology transformation of the industrial-scale Ti-1023 alloy ingot were investigated. The results indicate that the predicted grain growth direction (angle) of columnar grain at the bottom and edges of the ingot agrees with the actual one with coincidence degree more than 90% through temperature gradient components and . The temperature gradient-solidification rate (G-R) diagram was plotted. There is an obvious boundary between equiaxed and columnar grains, and the critical parameter G* for columnar-equiaxed crystal transformation varies under different melting processes.