A　perylene　tetracarboxylate　(PTCA)-based　organic　semiconductor　polymer　was　deposited　onto　an　indium　tin　oxide　(ITO)　glass　by　means　of　one-step　electrochemical　oxidation　at　a　constant　potential.　The　obtained　PTCA　thin　films　were　characterized　via　several　physicochemical　and　spectroscopic　methods.　The　thickness　of　the　deposited　film　can　be　controlled　by　tuning　the　deposition　time.　The　energy　of　the　lowest　unoccupied　molecular　orbital　and　the　optical　band　gap　of　the　film　(−2.1　eV,　3.6　eV)　were　higher　and　smaller,　respectively,　than　those　of　the　bare　ITO　(−4.8　eV,　3.7　eV).　Loading　a　PTCA　thin　film　onto　an　ITO　glass　created　a　type　of　photoanode　material　that　exhibited　enhanced　photocurrent　responses　and　improved　photoelectrochemical　water　oxidation　ability　compared　with　that　of　the　bare　ITO　film.　The　photoelectrochemical　ability　of　the　PTCA　film　array　(with　different　thicknesses)　for　water　oxidation　can　be　rapidly　screened　in　a　neutral　solution　through　the　substrate　generation-tip　collection　mode　of　scanning　photoelectrochemical　microscopy　(SPECM).　Among　the　array,　the　line　of　PTCA-600s/ITO　produced　the　largest　photocurrent　(9.2　nA)　in　a　0.1　M　KCl　solution　under　visible　light　irradiation.　Bulk　ITO　electrodes　decorated　with　the　film　under　the　same　preparation　conditions　confirmed　the　results　of　the　SPECM　screening.　In　addition,　SPECM　can　be　used　to　further　verify　the　photogenerated　carrier　transfer　mechanism　by　redox　competition　mode.　This　work　offers　insight　into　the　preparation　and　screening　of　photoelectrochemical　organic　semiconductor　material.　©　2020　Elsevier　B.V.