WO3 nanorods array films coated with SnO2 nanoparticles were prepared by hydrothermal method and electrochemical deposition method, and WO3/SnO2 heterojunction composite films were formed after annealing. The optimum preparation conditions were obtained by changing the deposition time of SnO2. The phase and morphology of WO3/SnO2 composite film were analyzed by XRD and FESEM. The photoelectric properties of WO3/SnO2 composite film were studied by electrochemical workstation. The results show that WO3/SnO2 composite film has the minimum impedance when the deposition time is 120 s. And its photocurrent density is 0.46 mA/cm2 at a bias voltage of 0.6 V, showing better photochemical properties than a single WO3 nanorod film.