Ti-doped WO3 films were prepared by mid-frequency dual-target magnetron sputtering method. The Ti-doped WO3 films were characterized with X-ray diffraction (XRD), Raman spectroscopy, ultraviolet spectrophotometer, chronoamperometry and atomic force microscopy (AFM) .The results indicate that after doping Ti, its crystallinity decreases at the same annealing temperature, and its surface roughness decreases dramatically with the increase of holes for ion injection and extraction, Accordingly, the response speed of the WO3 film doped with fraction of atom number 0.051 of Ti is greatly improved compared with the undoped film, and its cycle life is increased more than four times, but the spectral transmittance decreases after doping.