Underground space positioning device and method based on magnetic field full tensor gradient measurement

The invention relates to the technical field of oil and gas drilling, in particular to an underground space positioning device and method based on magnetic field full-tensor gradient measurement, and the underground space positioning device comprises a drill string, a magnetic dipole magnetic source nipple, a communication cable, a magnetic field gradient measurement exploring tube, a ground data receiving device, a computer and a power supply; and a preparation process, a data acquisition and transmission process and a data processing process. The device is reasonable and compact in structure and convenient to use, full-tensor magnetic field gradient measurement is carried out on an alternating magnetic field between a drilling well and a target well through a plurality of three-axis fluxgate sensors, and measurement errors caused by large external environment interference of a magnetic field gradient measurement probe can be effectively reduced; the magnetic field gradient measurement exploring tube is lowe