In order to investigate the dynamic crushing mechanism and energy consumption law of the ore at the microscopic scale, impact crushing tests were carried out on magnetite ore using a separated Hopkinson press bar, the crushing energy consumption law of magnetite ore was analyzed, and scanning electron microscope technology was combined to reveal the crushing mechanism of magnetite ore. The results show that under the impact load, with the increase of incident energy, the crushing energy consumption per unit volume and average strain rate of magnetite stone increase accordingly. The energy consumption per unit volume of crushing has a strong strain rate correlation and increases with the increase of average strain rate. With the increase of incident amplitude, the degree of magnetite crushing from the original specimen and the height of the broken pieces to columnar or needle-like, and the particle size of the broken pieces continues to decrease, and finally appearing in the form of powder, and the stepped crushing and wavy crushing morphology also increases, during which the phenomenon of magnetite outcropping occurs. With the increase of incident energy, the magnetite internal along the crystal cracks and perforated cracks continues to increase, the internal cracks are also gradually expanding and developing, the length of the cracks is converted from short and thin to long and wide, and the state of the cracks is converted into a wide crack state, and finally it is completely penetrated to the state of rupture. In the incident energy of 71.44 J, the perforated cracks are generated, and the number of along-crystal cracks is larger than the number of perforated cracks. The research results are helpful for improving the energy utilization efficiency of mines in crushing processes, and have certain theoretical significance for solving the current problem of high energy consumption in mine crushing.