The coarse north-seeking time of a mechanical gyro theodolite is an important factor to decide north-seeking efficiency.A quick coarse north-seeking method named curve fitting is brought into the intelligent gyro theodolite system in this paper.By the proposed method,the true north value can be obtained in 10 s after gyro operates through a counting cursor to calculate the movement velocity and acceleration,and it can also compensate the low precision caused by an electronic compass.The experiment using JT-15 gyro shows that the measurement precision is superior to 3′54″ when seeking coarse north,which meets the precise north-seeking condition of the JT-15 gyroscope.The application of the curve fitting method to the auto north-seeking system can ensure the velocity and precision of north-seeking automatically,and also has realistic significance to improve the efficiency and automation for mechanical gyro theodolites.