Hard　carbon(HC)is　considered　as　a　commer-cial　candidate　for　anode　materials　of　sodium-ion　batteries　due　to　its　low　cost　and　excellent　capacity.However,the　problem　of　low　initial　Coulombic　efficiency　is　still　urgently　needed　to　be　solved　to　promote　the　industrialization　of　HC.In　this　paper,2,2-dimethylvinyl　boric　acid(DEBA)is　used　to　modify　the　surface　of　HC　to　prepare　HC-DEBA　mate-rials.During　the　cycling,the　C=C　bonds　of　DEBA　molecules　will　be　in　situ　electro-polymerized　to　form　a　polymer　network,which　can　act　as　the　passive　protecting　layer　to　inhibit　irreversible　decomposition　of　electrolyte,and　induce　a　thinner　solid　electrolyte　interface　with　lower　interface　impedance.Therefore,HC-DEBA　has　higher　initial　Coulombic　efficiency　and　better　cycling　stability.In　ester-based　electrolyte,the　initial　Coulombic　efficiency　of　the　optimized　HC-DEBA-3％increases　from　65.2％to　77.2％.After　2000　cycles　at　1　A·g-1,the　capacity　retention　rate　is　90.92％.Moreover,it　can　provide　a　high　reversible　capacity　of　294.7　mAh.g-1　at　50　mA·g-1.This　simple　surface　modification　method　is　ingenious　and　versatile,which　can　be　extended　to　other　energy　storage　materials.