Blockchain, as a typical distributed system, its underlying networks highly influences the overall system performance and security. Blockchain networks differ from traditional P2P (peer-to-peer) networks in terms of security models, transmission protocols and performance indicators. This study first systematically analyzes the blockchain network transmission process, i.e., connection establishment and data transmission, and list out the challenging issues. Second, state-of-the-art blockchain topology protocols and data transmission methods are thoroughly investigated and discussed, from the perspective of node heterogeneity, coding scheme, broadcast algorithm and relay network, and etc. Meanwhile, the typical cross-chain network implementation and the network simulation tools are summarized. Finally, we envision the possible future research trends in the realm of blockchain networks.