Abstract: In this paper, the error characteristics of the zero compensation for the magnetometer are numerically analyzed by the Davis-Smith method under different relative amplitudes of compressional fluctuations. Our results show that as the relative amplitude of the compressional fluctuation decreases, the error of the zero compensation value for the magnetometer would decrease. When there is a wave in a certain component of the magnetic field with the same frequency as the compressional fluctuation, and the amplitude comparable to that of the compressional fluctuation, the zero compensation error of this magnetic field component will be relatively large. So we suggest that the reference value of the ratio of the average fluctuation amplitude of the magnetic field fluctuation to that of the compressional fluctuation ranges between 5 and 10; wherein the larger the reference value, the smaller the zero compensation error will be.