In response to the application requirements of drones in complex urban environments, a dual frequency band anddual channel data link system is developed for the S band telemetry and remote control link and the C band image transmission linkof drones. The focus is on breaking through the high reliability and efficiency of Orthogonal Frequency Division Multiplexing(OFDM) transmission system, efficient source channel joint coding technology, and solving the reliability, spectrum efficiency, anddata security issues related to data transmission. As the core transmission link of drones, the application of highly reliable andefficient drone data links will further expand the application scenarios of military drones and industrial grade intelligent drones.