The invention relates to a plane measurement method and an apparatus for a total field magnetometer measuring rock and a magnetic parameter of ore specimen. The employed plane measurement apparatus comprises a total field magnetometer, a specimen box with specimen in the box, a flat and flat supports. The total field magnetometer includes probes and probe supports. According to the invention, parameters measured by the total field magnetometer are inserted into formulas so as to obtain a magnetic susceptibility K and a residual magnetization Mr of specimen parameters. According to an appendix C of Technical Regulations on Ground High-precision Magnetic Survey in China, an apparatus of the total field magnetometer measuring rock and the magnetic parameter of the ore specimen is an oblique measurement apparatus. According to the invention, the oblique measurement is modified into plane measurement. Therefore, with utilization of the plane measurement apparatus, errors caused by inaccurate slope adjustment can be avoided. Moreover, with utilization of the oblique measurement apparatus, the rock and ore specimens are overturned and vibrated on the oblique surface, so that inclined displacement is caused and thus a maximum error of deviation in range is caused; however, the above-mentioned problem can be solved according to the invention. the plane measurement apparatus provided in the invention has advantages of simple structure and firmness; besides, the precision of the magnetic parameter measurement of the rock and ore specimens can be improved.