The safety of carrier aircraft and rocket is the foundation of inner air launch system. Linear theories with small disturbance and timedomain method are applied to study the stability、flying quality and safety during separation in cabin, and some ways are brought forward to improve flying quality. It is considered that rocket is likely to hit aircraft and the effect of carrier aircraft's pitch angle and rocket's location are simulated by using the kinematics equation of rocket. Through explosion comparability theory, the influence of rocket explosion wave on aircraft and pilot is taken into account and safe distance is obtained. The results of qualitative and quantitative analyses provide a theoretical basis for the application of inner air launch system.