Indium tin oxide (ITO) films were deposited on glass substrates by using the homemade injection ultrasound spray pyrolysis system. Orthogonal test was designed to examine the optimal conditions for preparation of the ITO films. The results showed that the ITO thin films can be prepared by the homemade injection ultrasound spray pyrolysis device successfully. The device is simple in structure and easy to use. The substrate temperature is the main factor on the photoelectric properties of the ITO films. The optimal conditions for preparing the ITO thin films were as following: the substrate temperature was 400°C, the carrier gas was argon, the injection speed was 0.4 ml.min611, the annealing temperature was 500°C, the distance between substrate and nozzle was 5.502cm, and the spray volume was 202ml. The average optical transmittance in the visible range and sheet resistance of the ITO film were 93.5°C and 210Ω/□, respectively.