Thermoplasmonics　originating　from　the　relaxation　process　of　plasmon　resonances　in　nanostructures　can　be　utilized　as　an　efficient　and　highly　localized　heat　source　in　solar-hydrogen　conversion,　but　there　have　been　few　researches　on　the　interfacial　heat　transport　properties　of　photoelectrode　with　the　thermoplasmonics　effect　in　a　photoelectrochemical　water　splitting　system.　In　this　work,　the　effects　of　temperature,　interfacial　coupling　strength　and　the　addition　of　graphene　layers　on　the　interfacial　thermal　conductance　of　Au-TiO2　electrodes　are　investigated　by　the　non-equilibrium　molecular　dynamics　simulation,　and　the　variation　of　interfacial　thermal　conductance　is　analyzed　by　the　phonon　density　of　states.　The　results　show　that　the　interfacial　thermal　conductivity　is　increased　by　78.55%　when　the　temperature　increases　from　300　to　800　K.　This　is　related　to　the　fact　that　more　low-frequency　phonons　participate　in　the　interface　heat　transport,　allowing　more　heat　to　be　transferred　to　TiO2　to　promote　the　interface　reaction.　As　the　coupling　strength　of　the　Au-TiO2　interface　increases,　the　interfacial　thermal　conductivity　of　the　electrode　increases　and　then　tends　to　stabilize.　The　interfacial　thermal　conductivity　can　be　optimized　by　increasing　the　degree　of　overlap　of　the　phonon　state　densities　of　Au　and　TiO2.　The　addition　of　a　single　layer　of　graphene　can　increase　the　interfacial　thermal　conductivity　to　98.072　MW·m–2·K–1,　but　the　addition　of　2　and　3　layers　of　graphene　can　hinder　interfacial　heat　transfer　in　Au　and　TiO2　due　to　the　interaction　between　the　layers　of　graphene.　When　adding　graphene　layer,　medium-frequency　phonons　and　high-frequency　phonons　are　stimulated　to　participate　in　the　interfacial　heat　transfer,　but　with　the　increase　of　the　graphene　layers,　the　number　of　low-frequency　phonons　in　a　range　of　0—30　THz　decreases,　and　these　low-frequency　phonons　make　the　greatest　contribution　to　the　interfacial　thermal　conductivity.　The　obtained　results　are　useful　in　regulating　the　thermal　transport　properties　of　the　photoelectrode　interface,　which　can　provide　new　insights　into　and　theoretical　basis　for　the　design　and　construction　of　composite　photoelectrodes.　©　2024　Chinese　Physical　Society.