The present invention relates to a technology for generating a stray field having a magnetic field direction according to an outer magnetic field by using a magnetic field conversion unit based on a magnetic particle, and detecting a magnetic field direction of the stray field through a magnetic sensor to detect a three-axis magnetic field. A three-axis magnetic field detection device according to an embodiment of the present invention may include a magnetic field conversion unit for generating a stray field having a magnetic field direction according to a magnetic field direction of an outer magnetic field by using a magnetic particle, a magnetic field measurement unit for measuring a magnetic field direction with respect to an X-axis magnetic field, a Y-axis magnetic field, and the stray field in relation to the outer magnetic field, and a magnetic field detection unit for detecting the X-axis magnetic field, the Y-axis magnetic field, and a Z-axis magnetic field on the basis of the measured magnetic field direction.
