Liquid propellant rocket engine is the power unit of a space vehicle, and thermal and combustion techniques are the core technologies, in which combustion, heat exchange, ignition, combustion control and liquid injection are included. Aerospace engines require that combustion and heat exchanger have high efficiency, igniters and control systems have high reliability, and liquid injectors have high capability. Since 1958, We successfully developed all kinds of main stream liquid propellant rocket engine combustion systems and solved many technical problems like combustion efficiency and stability. We established advanced thermal models, strength models and fluid models. These techniques established a solid foundation for the development of HTM-heaters, incinerators, etc.