Abstract: The telemetry system is responsible for obtaining the telemetry data of the whole rocket flight, which is the key to evaluate the comprehensive performance of the rocket afterwards. This paper introduces the overall scheme and composition of a new generation of large capacity FM telemetry system applied to Long March 5 carrier rocket. Focusing on the problems faced by the application of the key technology of 10 Mbps high bit rate FM telemetry, the technical breakthrough and flight test result are given from the aspects of the application of FM telemetry enhancement technology, the synthesis and transmission of hierarchical baseband data and the high gain antenna feed. Combined with the development process, the development experience and application of a new generation of large capacity FM telemetry system for rockets are summarized.