A theoretical solving approach of the multiple pounding forces taken place in bridge under near-fault vertical earthquakes is presented by the consideration of the rubber bearing. The bridge is simplified by a continuous model of beam-spring-rod, and solved by the expansion of transient wave functions in a series of eigenfunctions and the transient internal force method by the use of contact interfacial force of combined body. The numerical results show that the presented approach can solve reasonably the multiple pounding forces between deck and rubber bearing. The calculations of pounding forces and number of pounding in different vertical earthquake spectra, vertical earthquake periods, vertical earthquake amplitudes and span lengths of bridge, illustrates that the vertical pounding phenomenon can take place under near-fault vertical earthquakes, and damages the bridge before the horizontal earthquakes reaches. The present investigation exposes possibly the two conditions that may result in vertical poundings. One is when vertical earthquake periods is close to natural period of bridge. The other one is when the amplitude of vertical earthquake exceeds some threshold. In addition, the vertical pounding force varies in highly non-linearity with vertical earthquake periods, vertical earthquake amplitudes and span lengths of bridge.