The conversion of CO2to useful chemicals is of great significance for the mitigation of global warming. Among many methods of CO2utilization, photo-electrochemical CO2reduction is promising; however, the low activity of the photoelectrodes and the poor selectivity of the reduction products inhibit its practical application. In this research, CuFeO2nanoparticles (CFO NPs) are decorated on the CuInS2(CIS) thin-film surface by differential pulse voltammetry; at CFO NP-decorated CuInS2(CFO/CIS) thin-film photocathodes, CO2is reduced photo-electrochemically to methanol and ethanol, with methanol as the main product. Compared to the CIS thin-film photoelectrode, CFO/CIS thin-film photocathodes exhibit high activity of CO2reduction and good selectivity for methanol formation. The rate of methanol formation at the CFO/CIS thin-film photocathode at an overpotential of 0.17 V is estimated to be 15.40 mol h–1m–2, which is three times that at the CIS thin-film photocathode. The enhanced activity is attributed to the low mass-transfer resistance at the electrode surface. At CFO/CIS [−1.0/–1.2 V] deposited for 20 s, the lowest mass-transfer resistance can be obtained; methanol yield is therefore the highest. Methanol yield shows strong relationship with *CO coverage on the CFO/CIS thin-film electrode surface, while it shows no obvious relationship with *H coverage. In addition, CFO/CIS thin-film electrodes have high stability within 9 h.