The invention provides a blockchain-based cross-chain interconnection method, a blockchain-based cross-chain interconnection system, computer equipment and a computer readable storage medium, and relates to the technical field of information processing. The system comprises a cross-chain gateway node and a plurality of service chains, each service chain comprises an authority management node, a gateway node and a plurality of verification nodes, and the gateway node in the plurality of service chains and the cross-chain gateway node form a cross-chain gateway; and the cross-chain gateway is used for realizing message format standardization and a cross-chain conversion protocol among the plurality of service chains so as to promote adaptation and forwarding of cross-chain messages, support error processing of request message timeout during cross-chain interconnection and finally realize mutual access and intercommunication of cross-chain data. Mutual access among the alliance chains of a plurality of different block chain technologies is achieved by introducing the bridging gateway chain, the problem of information island among a plurality of block chain systems is solved, and application and popularization of the block chain technology can be accelerated.