The output position error of the polar inertial/satellite integrated navigation system continues to diverge under the ‘wandering system combination + grid system or lateral system output’ system. To avoid this problem, the divergence mechanism of the position error of the horizontal system or grid system is analyzed and verified, the inertial navigation arrangement scheme and the inertial navigation error equation under the Earth-centered-Earth-Fixed System (ECEF) are derived and the ECEF system inertial/satellite combined algorithm is designed. Finally, by solving the problem, it lays the foundation for the ultra-long-endurance lateral system or the grid system output global navigation under the inertial/satellite combined physique.According to the inertial navigation and satellite navigation data, the combined inertial/satellite algorithm of the wandering system and the combined inertial/satellite algorithm of the ECEF system are compared and analyzed, and the effectiveness of the combined inertial/satellite algorithm of the ECEF system in avoiding position error divergence is verified. It can better avoid the problem of position error divergence caused by the conversion of the output information of the polar navigation, and realize the high-precision and long-term integrated navigation of the polar region.