The fiber optic gyroscopes measure angular velocity based on the Sagnac effect, which is less disturbed by the external environment and has good autonomy. Therefore, the north seeking angle measurement system based on fiber optic gyroscopes has been used in a series of applications in the military field. In this article, the fiber optic gyroscope realizes high-precision north-seeking angle measurement by sensitive to the angular velocity components of the earth’s rotation at four positions. In order to meet the requirements of miniaturization, rapidity of individual soldier’s north seeking angle measurement, this paper studies the automatic and fast north seeking method of the individual soldier’s high precision north seeking angle measurement device based on single-axis fiber optic gyroscope under tilt placement. There may be interference in the measurement process of the device, which affects the accuracy of north seeking angle measurement. By studying the output characteristics of the sensor in the process of north seeking angle measurement of the device, and identifying and processing the interference, the high precision north seeking angle information is obtained. Finally, through experimental comparison and analysis, the effectiveness of the identification and process of interference under tilted conditions is verified to meet the needs of high precision north seeking angle measurement for individual soldier reconnaissance.