Abstract:WO3/Au composite film electrode was prepared by hydrothermal combined electrodeposition method. The samples were characterized by SEM, EDS and XRD and the results showed that WO3/Au composite film was synthesized. Electrochemical and spectral measurements were carried out to obtain the electrochromic conversion time, reversibility, coloration efficiency and transmittance of the samples. The photocurrent and photoelectric catalysis degradation efficiency were carried out to obtain photocurrent and photoelectric catalysis of the samples. The results show that compared with pure WO3 nanoblocks, WO3/Au composite film improves the electrochromic property, photocurrent and photoelectric catalysis activity. Among them, WO3/Au composite film prepared by depositing Au nanoparticles in 80 s showed the highest electrochromic property, photocurrent and photoelectric catalysis activity. Meanwhile, the photoelectric catalysis activity of the composite film is higher than its direct photocatalysis and electrocatalysis activity.