P2-phase　layered　cathode　materials　with　distinguished　electrochemical　performance　for　sodium-ion　batteries　have　attracted　extensive　attention,　but　they　face　critical　challenges　of　transition　metal　layer　sliding　and　unfavorable　formation　of　hydration　phase　upon　cycling,　thus　showing　inferior　long　cycle　life.　Herein,　a　new　approach　is　reported　to　modulate　the　local　structure　of　P2　material　by　constructing　a　state-of-the-art　in-plane　BO3　triangle　configuration　((Na0.67Ni0.3Co0.1Mn0.6O1.94(BO3)0.02).　Both　are　unveiled　experimentally　and　theoretically　that　such　a　structure　can　serve　as　a　robust　pillar　to　hold　up　the　entire　structure,　by　inhibiting　the　H2O　insertion　upon　Na　(de)intercalation　and　preventing　the　structure　from　deformation,　which　significantly　boost　the　long　cycle　capability　of　P2-materials.　Meanwhile,　more　Na　ions　in　the　architecture　are　enabled　to　site　on　the　edge　sharing　octahedrons　(Nae),　thus　benefiting　the　Na+　transportation.　Consequently,　the　as　produced　material　demonstrates　an　ultralow　volume　variation　(1.8%),　and　an　outstanding　capacity　retention　of　80.1%　after　1000　cycles　at　2　C.　This　work　sheds　light　on　efficient　architecture　modulation　of　layered　oxides　through　proper　nonmetallic　element　doping.　©　2022　Wiley-VCH　GmbH.