Finite　time　thermodynamic　optimization　theory　was　applied　to　optimize　the　performance　of　the　double-stage　coupled　heat　pumps　heating　system　(DSCHP).　The　irreversible　steady　flow　model　of　the　DSCHP　system　was　founded　considering　heat　resistance,　heat　leak　and　internal　irreversibility.　The　optimal　allocation　of　heat　exchanger　area　for　DSCHP　that　maximized　the　objective　function　(Coefficient　of　performance)　was　investigated.　The　optimal　temperatures　of　the　working　fluids,　the　minimum　total　heat　exchanger　area　and　the　minimum　power　input　were　determined　in　terms　of　the　analytical　expressions.　The　effects　of　the　three　irreversible　factors　on　the　system　optimal　performance　were　discussed　by　calculating　some　practical　cases.　The　optimization　results　could　guide　the　design　and　operation　process　for　the　DSCHP　system.