In　practice,　owing　to　the　unreasonable　defrosting　initiating　method　of　air　source　heat　pumps　(ASHPs),　mal–defrost　occurs　frequently,　further　leading　to　the　increase　of　building　heating　energy　consumption.　In　recent　years,　with　the　development　of　image　recognition　technology　in　many　fields,　it　has　been　expected　to　be　used　in　defrosting　initiating　control　methods　of　ASHPs.　Although　former　investigations　demonstrate　that　it　is　feasible　and　promising,　there　is　still　lack　of　a　control　strategy　to　make　it　become　reality.　To　promote　the　application　of　image　recognition　in　defrosting　initiating　method　of　ASHPs,　a　control　strategy　for　the　defrosting　initiating　method　based　on　image　gray　recognition　was　proposed　in　the　present　work　and　used　in　an　image　gray　recognition　equipment　(IGRE).　Then,　nine　groups　of　experiments　were　conducted　based　on　this　new　IGRE　method.　Results　indicate　that　the　proposed　control　strategy　for　the　IGRE　method　is　feasible　and　practical.　By　employing　this　new　IGRE　method,　the　defrosting　accuracy　rate　and　the　average　COP　of　the　ASHPs　are　respectively　42.86%　and　36.60%　higher,　compared　with　those　using　the　conventional　T–T　method.　In　complex　and　variable　environments,　the　defrosting　accuracy　rate　of　this　new　IGRE　method　reaches　93.33%　in　a　10–day　test.　©　2023　Elsevier　Ltd