Detection method of magnetic field gradient differential signal

The invention relates to a magnetic field gradient differential signal detection method. Generally, when the magnetic field gradients are measured, magnetic fields at two different positions need to be measured, and then subtraction is carried out to obtain the corresponding magnetic field gradients. In the method, the sensitivity coefficient to the total magnetic field is equal to the sensitivity coefficient to the magnetic field gradient, and the measuring range of the magnetic field gradient measurement is generally far smaller than that of the total magnetic field, so that the improvement of the sensitivity in the magnetic field gradient measurement is limited. The invention provides a magnetic field gradient differential signal detection method, the detection method has two output signals, and the sensitivity coefficient of the two output signals to a total magnetic field is far smaller than that of the two output signals to differential signals. Under the ideal condition that the sensitivity coefficient