Magnetic field component values

which is vertical to the geomagnetic field is put forward: the fixed coils electromagnetic induction method is adopted to detect the magnetic field

flux-gate sensor method is adopted to detect geomagnetic field

the magnetic field’s component values

which is vertical to the geomagnetic field

is calculated through the vector calculation. The magnetic field detection device is made. By comparing theoretical calculation with actual measurement of magnetic field’s radial component values and axial component values

the magnetic field detection device is proved to be effective. The influnence

which is caused by the excitation direction of coil changed

to a fixed point’s magnetic field component values

which is vertical to the geomagnetic field

is analyzed. The method to calculate the excitation coils ’ best direction is put forward. In this direction

a fixed point’s magnetic field component values

which is vertical to the geomagnetic field

is the biggest. As a result

it gives a theory guidence in the specific detection.