Vanadium oxide thin films were deposited by dual ion beam sputtering, and then annealled with different procedures of temperature elevating. Optical transmission properties were measured at different temperature by use of Fourier transform infrared spectrum, from which the relationship of transmission and temperature at a fixed wavelength of 5μm was obtained. The results show that the vanadium oxide thin film annealed with rapid elevating temperature has smaller and uniform crystal size, while the film annealed with normal elevating temperature has larger and wider distributed crystal size. All the films after annealing have abrupt change over 60% in transmission in infrared band. The phase transition temperature of vanadium oxide thin film after rapid elevating temperature annealing is 63.74℃, which is higher than that of vanadium oxide thin film after normal elevating temperature annealing, 60.31℃. The temperature range of phase transition of the former is also broader.