When the target is guided by multiple sensors, the traditional target azimuth is represented with the reference of the geographical north, while the geographical north converges in the north pole rapidly due to the convergence of the meridian in arctic region leading to the increase of the error of the target azimuth angle, which is unable to meet the demand information of target indication precision of combat command system of naval ship in arctic region. To overcome this problem, the establishment of horizontal geographic north as a reference is proposed, and on such basis, the geodetic theme solution model and the unscented Kalman filter model are constructed. The results of simulation analysis show that the method can improve the target (OTH) information accuracy as guided by the third party guidance in the high latitude region, it can satisfy the demand information of target indication precision of combat command system of the naval ship in Arctic region.