The rotating detonation engine (RDE) is a new engine system using detonation, which may provide a higher performance and smaller and simpler design in comparison with the pulse detonation engine (PDE) and other traditional engines. However the research on RDE stands just at the first step now. The authors perform a numerical analysis to understand about RDE in terms of features of rotating detonation and its propagation limit. The lower threshold pressure of detonation limit was 2.6MPa and the upper threshold pressure of detonation limit was 7.1MPa. The engine performance analysis shows that the maximum mixture based specific impulse (Ispm) was about 440s, which is comparable with that of the present typical rocket engine.