In order to analyze the effect of thermal behavior on microstructural evolution of laser deposition manufacturing process, a finite element model was constructed to simulate the temperature field distribution and thermal cycle characteristics. The simulation results showed that any node in substrate and deposition layer experienced heating or cooling cyclically. And the macro and microstructure of laser deposition manufacturing specimen were investigated to determine the evolution of microstructural features in multi-pass deposition layers. The macro and microstructures exhibited epitaxial coarse columnar prior β grains with basketweave or colony α lamella. The width of α lamella changed gradiently, and α lamella had basketweave Widmanstatten or colonies Widmanstatten morphology. The line scanning results by energy dispersive spectrometer (EDS) showed that major alloy elements, Ti, Al, Zr, Mo and V, were distributed uniformly from the substrate to deposited layer without fluctuation and segregation, which showed that evolution of microstructure was not a result of segregation but heat history.