[Purposes] This study explored the process of typhoon wave propagation with an aim to improve the storm surge defense capability. [Methods] This study proposed a superimposed wind field optimization method based on central node optimization algorithm and a wave-tide coupling model based on unstructured grid, the typhoon field and wave field of No. 1822 super typhoon "Mangkhut" in South China were simulated as an example. [Findings] The simulated values were compared with the measured values of buoys in the Pearl River estuary， the errors of key parameters of wind speed, wind direction, and effective wave height were generally small, indicating that the model accurately simulated the propagation process of typhoon waves during the typhoon process. Model simulation results showed that the effective wave height increased after Typhoon Mangkhut passed the Philippines and reached the maximum value of about 14.0 m in the early morning of 16th. After that, the wave spread to the Pearl River estuary and the outer sea area. Affected by the weakening of typhoon intensity, the shelter of island groups, and the decrease of water depth, the effective wave height gradually decreased. [Conclusions] The central node optimization algorithm proposed in this study can effectively reduce the wind field error in the transition region of the superposed wind field, and the wave simulation accuracy of the wave coupling model was improved by about 15% compared with the simple wind wave model. The wave height of the right semicircle of super typhoon "Mangkhut" was obviously larger than that of the left semicircle, which accorded with the law of typhoon "dangerous semicircle". Therefore, the wave height of Hong Kong (about 4.5 m) located in the right semicircle of "Mangkhut" was larger than that of Macao (about 3.6 m), Zhuhai and Taishan (about 2.3 m) which were closer to the typhoon path. The relevant results can provide reference for the study of storm surge along the coast of South China.