With the advance of process technology, electrostatic discharge (ESD) problem becomes more and more serious. To prevent design iterations caused by ESD failures, it is necessary to verify ESD protection network at design stage. In this paper, we present a full-chip analysis method of ESD protection network, which can analyze pad voltages for every pair of pads. Since the proposed method combines the merits of shortest path search and circuit simulation, it can analyze pad voltages more accurately than shortest path search with a little overhead of run time. The experimental results show that the proposed method can predict the reduction effect of pad voltage by ESD remedy. And it is shown that for a chip with 858 pads, the proposed method can analyze pad voltages of every pair of pads within 2 hours.