In case of aircraft fault or emergency right after takeoff, in order to ensure quick return landing and reduce the impact of emergency landing on aircraft and its maintenance, jettison system is necessary on large civil aircraft for quick inflight fuel jettison. This paper studies the airworthiness requirements of jettison system, summarized the legislative background, along with airworthiness requirements evolution and causes, and recommends compliance method. The method can be used as reference for civil aircraft jettison system design and airworthiness verification.