Based on the mobile contact and storage-carry-forward model, opportunistic mobile network can realize communication between nodes. However, establishing an efficient routing protocol is one of the key problems in opportunistic mobile network research. Based on the sociality of the opportunistic mobile network, many researchers have proposed a routing protocol to select the next packet relay node. However, the social features exploited from the history contact information take time to collect. Moreover, the protocol is unstable and cannot reflect the global contact information in the future, whereas an online social network of nodes can exploit the relationship between nodes all around and it is a stable relationship. By analyzing the stable online social network graph and the relationship between the online social network and offline contact network, we propose an opportunistic mobile network routing protocol based on multiple-level social relationship that combines the online friendship between nodes, the interests of nodes, and offline contact information to select the next hop node for the packet. Simulation results show that the algorithm significantly improves the success rate of data packet transmission and reduces the transmission time compared with the classical algorithms.