Metal　hexacyanoferrates　(HCFs)　are　viewed　as　promising　cathode　materials　for　potassium-ion　batteries　(PIBs)　because　of　their　high　theoretical　capacities　and　redox　potentials.　However,　the　development　of　an　HCF　cathode　with　high　cycling　stability　and　voltage　retention　is　still　impeded　by　the　unavoidable　Fe(CN)(6)　vacancies　(V-FeCN)　and　H2O　in　the　materials.　Here,　we　propose　a　repair　method　that　significantly　reduces　the　VFeCN　content　in　potassium　manganese　hexacyanoferrate　(KMHCF)　enabled　by　the　reducibility　of　sodium　citrate　and　removal　of　ligand　H2O　at　high　temperature　(KMHCF-H).　The　KMHCF-H　obtained　at　90(degrees)C　contains　only　2%　V-FeCN,　and　the　V-FeCN　is　concentrated　in　the　lattice　interior.　Such　an　integrated　Fe-CN-Mn　surface　structure　of　the　KMHCF-H　cathode　with　repaired　surface　V-FeCN　allows　preferential　decomposition　of　potassium　bis(fluorosulfonyl)imide　(KFSI)　in　the　electrolyte,　which　constitutes　a　dense　anion-dominated　cathode　electrolyte　interphase　(CEI)　,　inhibiting　effectively　Mn　dissolution　into　the　electrolyte.　Consequently,　the　KMHCF-H　cathode　exhibits　excellent　cycling　performance　for　both　half-cell　(95.2　%　at　0.2　Ag-1　after　2000　cycles)　and　full-cell　(99.4　%　at　0.1　Ag-1　after　200　cycles).　This　thermal　repair　method　enables　scalable　preparation　of　KMHCF　with　a　low　content　of　vacancies,　holding　substantial　promise　for　practical　applications　of　PIBs.