The　utilization　of　photoelectrochemical　cathodic　protection(PECCP)enables　an　indirect　corrosion　pro-tection　of　metals　with　low　self-corrosion　potential　by　introducing　a　metallic　nickel　interlayer.However,the　ability　to　enhance　the　PECCP　efficiency　remains　challenging　because　of　the　inherent　property　of　the　semiconductor.Herein,this　ability　is　demonstrated　by　coupling　a　covalent　organic　framework(TpBD)dec-orated　TiO2　photoanode(TiO2/TpBD)with　nickel　coating　on　magnesium　alloy　for　an　effective　corrosion　protection.The　composite　photoanode　showed　direct　PECCP　for　the　nickel　interlayer　and　indirect　corro-sion　protection　of　the　magnesium　alloy.The　composite　structure　of　the　nanotube　array　and　the　covalent　organic　framework　for　the　photoanode　were　confirmed　by　field　emission　scanning　electron　microscopy(FESEM),transmission　electron　microscopy(TEM),and　X-ray　photoelectron　spectroscopy(XPS).The　en-hanced　photoelectrochemical　conversion　capability　and　PECCP　performance　of　the　nickel-coated　Mg　alloy　were　evidenced　by　the　results　from　electrochemical　and　photoelectrochemical　measurements　including　Mott-Schottky　curves,photoinduced　potential　variations,and　electrochemical　impedance　spectroscopy(EIS).Lastly,a　corrosion　protection　mechanism　is　proposed,where　the　enhanced　PECCP　efficiency　is　at-tributed　to　the　formation　of　a　direct　Z-scheme　heterojunction,which　is　substantiated　by　the　results　from　valence　band(VB)XPS　and　electron　spin　resonance　characterizations.