Although some established electromagnetic particle detectors have been used to detect and distinguish micro-particles in different fields, the adopted particle equivalent model leads to large detection error because that ignores the difference of the magnetic perturbations induced by particles with different shapes and postures. To improve the development of high-precision electromagnetic micro-particle detectors, the magnetic models of particles with different shapes and postures are established. The distribution of magnetic flux density and the magnetic energy change caused by particles are calculated. The theoretical and experimental results illustrate that the change of magnetic energy caused by spherical particles is much lower than that caused by ellipsoidal and flaky particles of the same volume, meanwhile, with the increase of the rotation angle of ellipsoidal and flaky particles, the variation of magnetic energy decreases significantly. Based on the results, precise particle equivalent functions considering the magnetic properties of particles are proposed. (C) 2019 Elsevier B.V. All rights reserved.