Abstract: According to the field expression of arbitrary wire antennas obtained through the tensor method, this paper uses the mirror image method to give an analytical expression of the radiation field of impulse radiating antenna in time domain. The expression is then used to calculate the radiation fields of impulse radiating antenna applied to electromagnetic pulse simulator in time domain and the theoretical results are further compared with numerical ones. The results show that, the field waveforms calculated analytically are in good agreement with the numerical results; the effects of antenna parameters on antenna waveform can be easily observed by using analytical expressions, which can help to select appropriate values for parameters to achieve radiated field waveforms satisfying the standard requirements.