The invention discloses a joint cloud computing environment value exchange-oriented cross-chain communication method, and aims to ensure the security, reliability and high efficiency of a value exchange process. According to the technical scheme, a cross-chain communication system consisting of a cross-chain communication module, a node management module, a verification module and an accounting module is installed in each user node on each block chain; a midchain is established; a route node is selected from the midchain; value transfer and communication between chains are finished by the route node; the cross-chain communication module of a sender constructs a fund pool for the sender, a receiver and the route node, and performs fund transfer according to a fund transfer scheme; the verification module of the receiver verifies the effectiveness and availability of funds of the sender by adopting a smart contract; the accounting module of the receiver broadcasts a transaction result; and the sender, the receiver and the MidChain generate new blocks for storing transaction data. By adopting the method, the security, reliability and high efficiency of the value exchange process can be ensured; and seamless cross-chain communication between the chains is realized.