The invention discloses a low-altitude rescue aircraft route planning method based on three dimensional airspace grids. The low-altitude rescue aircraft route planning method comprises that according to the three dimensional terrain, the aircraft performance and the weather distribution, the low-altitude airspace is divided into grids, nodes are generated, and the optimal flight path of a single aircraft is searched by means of an improved A* algorithm; on the basis that the flight path of the single aircraft is determined, by means of a time window estimation method, a time-space-interchange multi-aircraft conflict-free route planning method is provided, finally the shortest rescue time is taken as the optimization object, and a multi-aircraft conflict-free route planning scheme is obtained. According to the invention, an aviation rescue multi-aircraft conflict-free route planning method which takes the low-altitude complex terrain, the weather distribution and the aircraft performance into account, and a basis can be provided for the arrangement of the aircraft flight plan of an aviation emergency rescue command system.