Abstract: Aiming at the real-time requirement of geomagnetic matching navigation,an orthogonal search method based on inertial error characteristics was proposed.Based on the analysis of inertial navigation error characteristics,this method was arranged to adopt an orthogonal search strategy to perform orthogonal search on the geomagnetic data sequence of the matching point after interpolation along the vertical direction and the parallel direction of the flight trajectory respectively,to quickly obtain the best matching result.Extending the geomagnetic data of the ground measurement to different heights,the proposed method and the global search algorithm were used to process geomagnetic data.The data processing results show that the method in this paper has the same matching accuracy as the global search algorithm,but it can reduce the search time and can effectively improve the real-time performance of the matching and positioning method of high-speed high-altitude aircraft.