Abstract：According to the extreme mechanical and thermal environment of large thrust rocket engine during operation, the mechanical characteristics of large thrust liquid rocket engines, such as strong vibration, large static load, multi-source excitation and complex load transfer path, are expounded and analyzed. In the aspect of statics, the whole engine structural load analysis and the component static analysis method are introduced. In the aspect of dynamics, the low-frequency structural dynamic model of the whole engine, the refined model updating technique and multi-source load equivalent method are introduced. For the typical engine components, the mechanical challenges faced in the development of large thrust engine are summarized, including high-temperature and high-pressure gas swing device, rotor dynamics, dynamic and static interference fluid excitation, cavitation oscillation in inducer, large range axial force balance, supersonic turbine flutter, thermal fatigue of thrust chamber, lateral force load of nozzle, fatigue fracture of assembly pipeline, etc. The mechanical requirements and future research directions are pointed out. Finally, the status of probabilistic failure analysis of the engine is briefly introduced, which provides mechanical support for the development of large thrust liquid rocket engine.