The internally carried air-launched launch vehicle has the characteristics such as separating time of rocket and plane is short and the distance between plane and rocket is short. The explosion of rockets is a factor affecting safety that need to be thought in the process. The objective function with explosion wave stamping, carrier aircraft surface overload for variables was set up based on the similarity theory method of explosion. It is gotten that explosion wave front pressure with explosion wave propagation distance curve and position relation table between rocket and plane on special super pressure according to initial trajectory dynamics equation of the rocket in the end. The safety distance is confirmed, which provides reference in theory for launch experiment and air launch.