In response to the problem of slow computation speed of the existing airspace characterization model based on the grid profile of latitude and longitude, which has large grid deformation at high latitudes, and the conflict detection algorithm that determines whether the airspaces overlap with each other by the airspace boundary coordinates, we propose to characterize the airspaces with the full equal rhombic discrete grid based on the large circular arc profile of the spherical rhombic discrete grid of positive icosahedron, and use the multi-level Hilbert space filling curve to encode the airspaces uniformly by combining the airspace priority. A matrix-based digital airspace representation method is designed, and the Hadamard product operation is used to quickly determine whether there is a conflict between the space-use attributes of multiple airspaces. The simulation results show that the method has high grid accuracy, achieves second-level conflict detection, and can achieve the purpose of reducing the algorithm operation and improving the operation speed compared with the traditional conflict detection algorithm.