Against the background of point air defense combat, an assessment method of covering capability of point air defense weapon is proposed under the given position deployment conditions. The definition of covering area is given combining with the maximum route shortcut and the covering depth; and the solutions of covering angle range are discussed respectively when the firing area is bigger than/equal to/smaller than bomb-dropping area. The detailed solution method of the two circumstances is proposed combing with the maximum route shortcut, its corresponding azimuth angle and the intersection azimuth angle. The validity and adaptability of the method is verified through simulation.