A high-accuracy geomagnetic vector measurement method is characterized in that a vertical additional
magnetic field and a horizontal additional
magnetic field which have the same intensity but different directions are added to the position of a probe of a high-accuracy total-field
magnetometer; a geomagnetic field without additional magnetic fields and a
resultant magnetic field with an additional forward magnetic field and an additional reversed magnetic field are measured respectively; and then, each component, including a vertical component Z, a horizontal component H, a geomagnetic inclination I and a
declination D, of a geomagnetic vector can be computed, and the method is suitable for fast and high-accuracy geomagnetic vector measurement outdoors or in a fixed
station. According to the method, the geomagnetic vector measuring accuracy is in
positive correlation with the accuracy of the matched
magnetometer, and the high-accuracy total-field
magnetometer is superior to a fluxgate three-component magnetometer with 10 nT of measuring errors. A high-accuracy geomagnetic
vector field measurement device comprises one group or two groups of field coils and a tripod, the field coils are added to the outside of the high-accuracy total-field magnetometer probe, and the field
measurement device is matched with the high-accuracy total-field magnetometer and used for rapidly measuring each component of the geomagnetic vector outdoors or in the fixed
station.