The invention discloses a north finding measurement method used for a pendulum-typed gyro north-finding instrument, in particular to a north finding method which automatically tracks the orientation swing of the gyro pendulum body and applies a slipform control technique. The method is characterized by comprising the steps as follows: step 1: by over-damp control, the initial state of north-finding control of the gyro pendulum body is established, the swing angular speed of the pendulum body quickly attenuates to zero and the torque zero position and the photoelectric zero position of the pendulum body are consistent; step two: the over-damp control is released, and the pendulum body swings in a no-damp way; when the pendulum almost motions to 1/4 period, the over-damp control is started and leads the pendulum body to quickly tend to true north; and step 3: the step 2 is repeatedly for many times so as to lead the pendulum body to approach to true north. The technical proposal of the method can achieve the object of finding north quickly and automatically and meeting the requirement in the engineering that north is quickly and automatically found.