Method for determining drift-down failure points

The invention relates to a method for determining drift-down failure points. The method comprises the following steps: specific to each key barrier, calculating a failure point position corresponding to the key barrier based on a distance between an influence boundary of the key barrier and a starting place of an airway and a distance between the influence boundary of the key barrier and a failure point; and determining the failure points capable of crossing all key barriers as the drift-down failure points in the failure points corresponding to all key barriers.