Abstract: Disclosed is an apparatus for opening an upper and lower split-type airframe hinge-coupled to a propulsion unit of a missile and separating a payload mounted in the airframe. The apparatus for opening the airframe of the missile by pyrotechnical power includes: pressure generation units installed between the airframe and the payload, for generating explosion pressure; and pressure transmission units connected to the pressure generation units, for applying force by the explosion pressure to the payload, and opening the airframe by reaction force with the payload. The apparatus for opening the airframe of the missile reduces an installation space and cuts down a manufacturing cost by simplifying the configuration by decreasing a number of components, improves airframe opening performance by instantaneously opening the airframe in exact timing, and enables the user to adjust airframe opening force in a target level.