The construction of integrated data center provides data support services for energy smart city, which is inseparable from the aggregation of various data, such as electricity consumption information and power related data all over the city. Therefore, a stable and efficient data transmission system is needed to complete the data transmission work. But in reality, there are some problems such as the complexity of the public network environment, the diversity of data sources, and the security of source data. In order to solve the above problems, the data transmission system needs to have the following core functions: message forwarding, routing exploration, concurrent transmission, encrypted transmission, breakpoint continuation, error retransmission, etc. Based on socket communication, the system constructs a routing path from the source to the data center by exploring the routing nodes. By encapsulating the messages, the messages exchange and forward the information between the paths. For the source data with high security requirements, it encrypts the transmission. At the same time, it designs the transmission failure protection mechanism, which leads to connection problems in the transmission process, Connection recovery can continue transmission; at the same time, it can continue transmission for some unfinished tasks; it can automatically resend the failed data.