Abstract: In order to study the blocking effect of digital communication stations radiated by electromagnetic pulse trains, an electromagnetic pulse injection test was performed on a digital communication station. The bit error rate (BER) of radio stations following the change of amplitude and repeat interval of electromagnetic pulse trains was studied. The results show that the BER increase monotonously at the beginning and then changes in different ways with the increase of pulse amplitude. Because there is big different in BER when the pulse repetition rate is different, a certain BER cannot be used as a susceptibility criterion. But according to the relationship between the BER and the pulse repetition rate, the susceptibility criterion of BER under any repetition rate can be given.