In the past, the typhoon abnormal waves have caused disasters in Number 11 Highway. For instance, the fundations of Number 11 Highway were exposed when the Sudil typhoon (2015) and Trami typhoon (2018) attacked, and there were wave attacks in Number 11 Highway during Megi typhoon (2016). As a result, in the study, in order to estimate the influence of wave attack, the wave attacking news were collected, and eight of which were simulated under typhoon-like situation by XBeach. Due to the news and XBeach simulation have showed that the Jentingshengtien section in Number 11 Highway is likely influenced by wave attacks, we simulated seven cross sections of the Jentingshengtien section under different situations by COBRAS model. This method can build a situation database and develop the wave attack early warning system to estimate the hazard. In addition, refer to the assimilation method of Ou et al. (2004) to assimilate and modify the significant wave height forecast of SWAN, so as to improve the accuracy of the Taidong Coastal Highway wave attack warning system.