A sensor system suit for three-dimensional pyromagnetic field detecting is presented. That weak magnetic field concomitantly occurs with deformation heat on loading procedure of prefabricated defects polymer materials. The main technical parameters of sensors and the technical measures to improve sensor sensitivities are briefly introduced, including the treatment method for background magnetic field. The hardware structure and the software flow of data acquisition system for this three-dimensional pyromagnetic field detecting are provided. As an applied result, a sort of 3D component curves o...