Abstract: The theory of the connector and the subsection modeling was propounded. For the disadvantages of the magnetically insulated line oscillator (MILO) and antenna designed separately, a kind of system simulation method was proposed, and was completed by using finite-difference time-domain and particle-in-cell algorithm and message passing interface. In the simulation, a phenomenon was found that a amount of power from the antenna reflected into MILO, and the effective method to reduce the impact of reflected power was got. Results show that metal strut rods could filter out DC power, and the maxium output power of the antenna is 6.2 GW, which also proves the validity of the method.