Abstract: Conflict detection between airspaces is key to ensure the orderly implement of all kinds of air activities. In view of the disadvantages of the traditional spatial conflict detection methods, such as low computational efficiency and complex spatial calculations, this paper proposes a spatial conflict detection method based on Gilbert-Johnson-Keerthi algorithm (GJK algorithm) under the GeoSOT grid system. Firstly, grid is used to represent the spatial domain based on the advantage of grid in space-time binary calculation. Secondly, combined with the minimum safety interval in airspace, a safety bounding box in airspace is constructed, and the grid coding set of the bounding box is transformed into the set of coordinate points. Finally, GJK algorithm is used to transform the intersection detection between two special bounding boxes into the judgment of the inclusion relationship between the Minkowski difference set and the origin of coordinates. The simulation results show that this algorithm can effectively detect conflicts in airspace and provide a new technical means and practical ideas for airspace conflict detection.