Two-dimensional　(2D)　hybrid　perovskite,　which　has　inherent　optical　anisotropy　and　structural　properties　shows　broad　application　prospects　as　a　polarization-sensitive　candidate.　In　particular,　the　polar　members　that　enable　the　bulk　photovoltaic　effect　(BPVE)　show　great　potential　in　self-powered　photodetection.　Here,　by　incorporating　a　brominated　aromatic　cation　as　an　interlayered　spacer,　we　have　succeeded　in　synthesizing　a　polar　2D　hybrid　perovskite,　(BBA)(2)(MA)Pb2I7　(1,　where　BBA(+)　is　4-bromobenzylammonium,　MA(+)　is　methylammonium).　The　inherent　structural　anisotropy　caused　by　the　alternate　placement　of　inorganic　perovskite　sheets　and　organic-spaced　cations　permits　substantial　linear　absorption　dichroism　with　a　high　ratio　of　similar　to　4.2　(at　520　nm).　Moreover,　the　bromination　of　the　organic　spacer　favours　the　electric　polarity　of　1.　The　electric　spontaneous　polarization　(P-s)　results　in　notable　BPVEs　in　1,　which　directly　drives　the　separation　and　transport　of　photoexcited　carriers　and　further　supports　its　self-powered　capability.　As　expected,　the　self-powered　photodetector　of　1　exhibits　strong　polarization　sensitivity　to　linear　polarized　light,　showing　a　polarization　ratio　of　4.8.　This　figure　is　even　larger　than　that　of　conventional　inorganic　GeSe　nanosheets　(similar　to　1.09　at　532　nm).　This　work　will　facilitate　the　potential　application　of　2D　polar　perovskite　candidate　materials　for　self-powered　photodetection.