In order to solve the problem that high precision azimuth measurement can not be realized due to the fit clearance when the gears of two-position and four-position fiber optic gyroscope (fog) north finders are engaged, a new V-shaped groove positioning mode is designed, and the design scheme of the key structures is introduced, including the transposition structure assembly, the limit drive assembly and the transposition drive assembly, and the azimuth calculation formula of the fog north finder in the state of level and inclination is derived; In order to determine the anti-vibration performance of the designed fiber optic gyroscope north finder, the simulation analysis is carried out. The simulation results show that the safety factor and the maximum deformation meet the engineering requirements.The test accuracy of roll angle, pitch angle and azimuth angle and the repeatability accuracy of roll angle, pitch angle and azimuth angle of the north finder are measured by experiments.