Disclosed is a data sharing method, including: building a trust alliance block chain, the trust alliance block chain comprising a main chain and at least one slave chain; each slave chain corresponding to a domain; and each domain comprising a leader node; establishing a virtual slave chain on the trust alliance block chain; designating, by the leader node in each domain, a node as a federated learning node; assigning, by the leader node in each domain, a virtual identity to the federated learning node to join the federated learning node to the virtual slave chain; and performing, by each federated learning node, a joint training on a local federated learning model using data generated in its own domain to establish a public federated learning model, through which data are shared among the domains. The present disclosure further provides a data sharing system, an electronic device and a storage medium.