The design of speedy exit runways for an airfield is an important problem in airport engineering. For the civil aviation, the specifications of FAA and ICAO can be used. But for an airfield used by small airplanes, some problems will crop up. From an analysis of the representative plane of the speedy exit, it is shown that it can be divided into two segments: the turnoff and the fillet. The part of the turnoff can be described by the turning radius and the turning angle, the other part of the fillet can be described by the offset of the airplane. So these are the parameters to be studied. Through analyzing the landing track of the airplane on the runway, the relations between the exit angle and the distance of the runway to the taxiway, and between the offset in the fillets and the distance of the exit are obtained for 5 types of airplanes making swerves at the speeds of 10,15,20m/s,25 and 30. In the end, the paper put forward a new design method for the radii R, the exit angle and the fillet, for the design of speedy exit runways of military airfields.