Aiming　at　the　coordination　problem　of　dual-channel　closed-loop　supply　chain,　a　dual-channel　closed-loop　supply　chain　decision　model　with　a　manufacturer,　a　retailer　and　a　third-party　was　established　based　on　game　theory.　The　influence　of　centralized　decision-making　and　decentralized　decision-making　on　optimal　pricing　strategy　and　optimal　supply　chain　members＇profit　was　analyzed,　and　the　efficiency　loss　of　dual-channel　closed-loop　supply　chain　was　leaded　by　decentralized　decision-making.　To　make　up　for　such　efficiency　loss,　a　profit　and　expense　sharing　contract　was　designed　to　realize　the　coordination　of　dual-channel　closed-loop　supply　chain　based　on　the　optimal　result　of　centralized　decision-making.　The　effectiveness　of　the　profit　and　expense　sharing　contract　was　verified　through　a　numerical　example.