Vanadium thin films are deposited by magnetron sputter. Then VOx thin films are fabricated by a series of rapid thermal processes (RTPs) in pure oxygen environment. X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscope are employed to analyze crystalline structure of the thin film, phase composition and surface morphology. Electrical and optical properties of VOx thin film are measured by the four-point probe method and THz time-domain spectroscopy technology, respectively. The results reveale that the VOx thin film which is composed mainly of V2O5 and VO2 has the properties of phase transition to a certain extent within the RTP condition of heat preservation temperature and time, and the overall valence of vanadium remains unchanged, no matter whether the RTP condition is the same. The best performance VOx thin film can be obtained under the moderate RTP condition, such as 500 ℃ 25 s, and this film can also modulate the THz wave.