It is found that the samples usually melt and even gasify in the magnetic driven high-speed flying plate experiments, which phenomenon goes against the investigation on materials’ equation of state (EOS). To understand this phenomenon, the whole process of magnetic driven flying plate experiment is simulated by the magnetohydrodynamic code MDSC. The ablation mechanism of magnetic driven flying plate is analyzed through the control of thermal conduction coefficient, and resistivity coefficient which is related to the magnetic diffusion velocity, in the energy conversing equation. Inside the flying plate the velocity of stress wave is much higher than that of magnetic diffusion, and hence the current goes into the inside of sample no early than the stress wave, so the magnetic diffusion doesn’t play an important role in the first stage of flyer free surface velocity history. The thermal conduction doesn’t influence the whole free surface velocity history of the flying plate much, while the Ohmic heating has a big effect on it, without which more than 20% error will be produced. The energy transportation in the flying plate medium is mainly caused by the Ohmic heating from magnetic diffusion. Besides, the relationship between the magnetic diffusion and temperature of flying plate is also analyzed.