Abstract: In this paper, the parallel finite-difference time-domain method (FDTD) computation using 200 000 CPU cores is firstly implemented on "Tianhe-2" supercomputer which is ranked the first in the world currently. Under different test scales, the parallel efficiency is 50% on 100 000 CPU cores and 200 000 CPU cores with 10 000 CPU cores and 100 000 CPU cores as benchmark respectively, which shows the good scalability of the method. Two typical microstrip array simulation examples with 1 984 and 3 968 elements indicate that the radiation of large microstrip antenna array can be analyzed efficiently using the proposed method.