Covalent　organic　polymers　(COPs)　memristors　with　multilevel　memory　behavior　in　harsh　environments　and　photoelectric　regulation　are　crucial　for　high-density　storage　and　high-efficiency　neuromorphic　computing.　Here,　a　donor–acceptor　(D–A)-type　COP　film　(Py-COP-3),　which　is　initiated　by　keto–enol　tautomerism,　is　proposed　for　high-performance　memristors.　Satisfactorily,　the　indium　tin　oxide　(ITO)/Py-COP-3/Ag　device　demonstrates　multilevel　memory　performance,　even　in　high　temperatures,　acid-base　corrosion,　and　various　organic　solvents.　Moreover,　the　performance　can　be　modulated　by　the　photoelectric　effect　to　maintain　a　great　switching　behavior.　By　contrast,　Py-COP-0,　with　similar　structure　and　chemical　composition　to　Py-COP-3　but　without　keto–enol　tautomerism,　exhibits　binary　storage　performance.　Further　studies　unravel　that　both　the　formation　of　conductive　filaments　and　charge　transfer　within　D-A　Py-COP-3　film　contribute　to　the　resistive　switching　behavior　of　memory　devices.　©　2023　Wiley-VCH　GmbH.