Abstract: Electromagnetic pulse attack (EMPA) is a severe threat to the security of integrated circuits. Considering that on-chip power distribution network is highly susceptible to electromagnetic pulse, in order to resist the electromagnetic pulse attack, a method is proposed to analyze the IR drop distribution in the network under EMPA. First, at the integrated circuit floorplanning stage, the on-chip power distribution network model and the EMPA model are constructed based on finite element simulation. The distribution of induced current density on the power distribution network under EMPA is simulated and the induced current is calculated. Next, the induced current is loaded into the power distribution network model, and the IR drop distribution is analyzed using IR analysis tools. The IR drop in a layout based on TSMC 180 nm process is analyzed, and the result shows that the EMPA can trigger IR drops above 2.3 V in the power and ground networks. Compared with existing analysis methods based on the theoretical value of current distribution, the proposed analysis method can obtain the IR drop distribution in the power distribution network under EMPA more accurately. This analysis method can be used to guide the improvement of power distribution networks and enhance the ability to resist EMPA. The experimental results show that after adding a set of power/ground pads, the maximum IR dropss in the power and ground networks are reduced by 28% and 24%, respectively.