The invention discloses a PIN diode time domain equivalent circuit model. The model comprises four sub-circuits, wherein the first sub-circuit describes an I-layer equivalent circuit and a PN junction equivalent circuit, the second sub-circuit and the third sub-circuit are combined with the PN junction equivalent circuit in the first sub-circuit to describe the relation between PIN diode current and PN junction voltage drop together, and the fourth sub-circuit is combined with the I-layer equivalent circuit in the first sub-circuit to describe the relation between PIN diode current and I-layer voltage drop. The invention further provides a modeling method of the PIN diode time domain equivalent circuit model. The PIN diode time domain transient equivalent circuit model can be established to reflect the peak leakage and recovery time of the charge-storage effect so as to precisely predict the time-domain response characteristics of a PIN diode under the action of various signals, and then a method is provided for predicting the electromagnetic pulse effect of the radio frequency front end of sensitive electronic information equipment.