The utility model discloses a nonmagnetic full-sealed three-shaft fluxgate magnetometer, and the magnetometer comprises a housing, a full-sealed cavity, a measurement coil, and a magnetic core. The full-sealed cavity is provided with a plurality of welding pins through glass sintering. The full-sealed cavity, the welding pins and the housing are all made of nonmagnetic alloy materials which have the same expansion coefficient with glass. The measurement coil comprises three orthogonal measurement coils. The center of the three measurement coils is provided with a common magnetic core, thereby forming a three-shaft fluxgate. The interior of the full-sealed cavity is provided with an exciting circuit and a measurement circuit in an integrated packaging manner. The measurement coil, the magnetic core and the circuit are all disposed in the full-sealed cavity, and connecting lines of the measurement coil, the magnetic core and the circuit are led out through the glass-insulation welding pins. Through the developing of nonmagnetic alloy and packaging glass, which have the same expansion coefficient, and the technology of nonmagnetic full-sealed glass packaging, the magnetometer is enabled to be in the state of zero stress in a very wide range of temperature, and can carry synchronous precise measurement for three components of a magnetic field at one point in the space.