The V2O5 thin film was prepared on the substrates of Si glass and commercial glass by the sol-gel technique. The samples prepared were annealed in air atmosphere at different temperatures. The microstructure, the morphology and optical properties of V2O5 thin films were studied by XRD, SEM and spectrophotometer. The results of XRD and SEM indicate that the better crystalline states and orientation with V2O5 (001) and (200) after annealing can be obtained, and the grain homogeneity on nano-V2O5 film surface can be improved through proper increasing of annealing temperatures; The results of transmission and absorption spectra show that a red shift will occur at the absorption edges of V2O5 films, and optical band gaps are shortened gradually with the increase of annealing temperature.