A storage network structure comprises a primary distributed storage network (a cluster distributed storage network or a DHT (Distributed Hash Table)-based peer-to-peer storage network) and a Peterson graph-based storage network. The storage network structure provides different reliability classes for applications and combines the advantages of a peer-to-peer based distributed network storage with Peterson graph-based network storage, solve the problem of a large quantity of data migrating by utilizing the better media data migrating non-movable property from the Peterson graph-based network storage, and screen the single failure of the cluster storage structure and avoid performance degradation of peer-to-peer wide area storage by combining with the availability and robustness of Distributed Hash Table.