The　indoor　space　of　residential　building　is　limited,　especially　in　building　retrofit,　to　improve　the　indoor　space　utilization　and　the　performance　of　exhaust　air　heat　recovery　system,　a　novel　dual-cylinder　rotary　compressor　with　independent　suction　and　discharge　ports　was　designed　to　drive　an　inverter　parallel-loop　exhaust　air　heat　pump.　Through　the　experiments　and　analyzing　the　parallel-loop　exhaust　air　heat　pump　system　working　characteristics　under　variable　compressor　frequency　and　different　fresh　air　volume　flow　rate,　the　optimized　method　is　proposed　and　verified　experimentally.　Finally,　the　annual　energy　efficient　operation　plan　was　proposed,　and　the　seasonal　performance　factor　and　seasonal　average　input　power　under　this　operation　plan　in　three　typical　countries/organization　were　calculated.　Results　show　that　the　system　COP　can　be　greatly　improved　by　applying　a　mixed　air　supply　method　during　winter.　When　the　fresh-air-to-return-air　ratio　is　1:1　and　the　outdoor　temperature　is　-5　degrees　C,　the　system　COP　reached　10.18,　which　is　the　highest　comparing　with　the　related　studies.　In　summer,　the　system　COP　is　increased　by　increasing　the　ventilation　volume　flow　rate.　When　the　operation　of　the　parallel-loop　exhaust　air　heat　pump　system　follows　the　energy　efficient　operation　plan　to　ensure　the　temperature　effectiveness　over　100%　and　the　outdoor　working　condition　complies　with　GB　21455-2013,　the　heating　season　performance　factor,　heating　season　average　input　power,　cooling　season　performance　factor,　and　cooling　season　average　input　power　are　7.22,　0.6909　kW,　2.83,　and　0.8167　kW,　respectively.　The　work　would　provide　guidance　for　the　development　of　exhaust　air　heat　recovery　system　in　residential　building.