关键词: 运载火箭, 推进系统, 总体设计, 动力技术, 低温火箭发动机, 关键技术

Abstract: The development history of CZ-5 launch vehicle has been briefly reviewed. Combining with the development situation of the launch vehicle propulsion system abroad， the design criteria and overall scheme of the propulsion system of CZ-5 launch vehicle have been summarized. Details of a series of new technologies of propulsion system with independent intellectual property rights during the development led by CZ-5 have been deeply included， including new generation powerful rocket engines， circulation precooling， cryogenic rocket POGO（the longitudinal instability and low frequency vibration caused by the coupling of the dynamic characteristics of the liquid launch vehicle structure system and propulsion system） restriction， high reliability of pressurization transportation system， test run of 5m diameter LOX/LH₂ propulsion system and unattended on-site operation during test and launch stage. At the same time， the new expectations for the future requirements of CZ-5 propulsion technology and maintenance improvement have been suggested， such as continuous improvement of cryogenic rocket engines， whole process automatic test and launch，propulsion system fault diagnosis，advanced POGO restriction and long-termed on standby and on orbit.

Key words: Launch vehicle, Propulsion system, System design, Propulsion technology, Cryogenic rocket engine, Key technology