In order to solve the problem that the defect location error of the oil and gas pipeline defect is accompanied by the increase of the measurement distance, the Honeywell’s three-dimensional magnetoresistive chip is used to design the ground marker for correcting the positioning error by using magnetic information. The marker uses modular design, including ARM processing platform, signal acquisition and storage, GPS timing and data wireless transmission of four parts. It is possible to realize the acquisition and storage of the magnetic disturbance signal generated by the internal detector, and to reduce the noise of the magnetic field signal by using the sensitivity of the wavelet transform to the singularity of the signal, and to calculate the internal detector through the ground marker Just below the exact moment. The design scheme improves the accuracy and reliability of the ground marker, and has certain reference value.