Two-dimensional　C3N　has　attracted　various　attention　owing　to　its　excellent　electrical　and　mechanical　properties.　However,　a　critical　issue　is　that　the　trap　of　Li,　introduced　by　the　vacancy　defect　during　experimental　preparation,　will　weaken　the　performance　of　the　batteries.　In　this　work,　atom-doped　regulation　is　proposed　to　repair　the　vacancy　and　further　improve　the　performance　of　pristine　C3N.　The　calculated　formation　energy　indicates　that　C　and　B　atoms　are　more　favorable　to　appear　as　compared　to　other　atoms　such　as　Si,　P,　and　N　atom.　Moreover,　the　Li　ionic　conductivity　and　the　binding　energy　of　Li　on　doped　C3N　are　greatly　improved　compared　to　pristine　C3N　without　the　sacrifice　of　mechanical　properties,　and　migration　capability.　These　studies　could　provide　theoretical　guidance　for　the　realization　of　high-performance　C3N　anode　materials.