Abstract: Working principle of magnetic core in linear transformer driver(LTD) was introduced. The influence of the magnetic core’s volt-second product on the output of LTD was deduced by means of simulation. A series of experiments were designed to evaluate the saturation of the magnetic core. These experiments were carried out under such conditions as different volt-second product of the core, different reset state of the core and different load resistance. Conclusions as the criteria of magnetic core saturation and reset effects of reverse current to magnetic core were drawn from the experiment results. The experiment results validate the simulation results. Application of the saturation effect of magnetic core to specific fields were suggested.