The estimation of significant wave height (SWH), especially under extreme conditions, is crucial for the understanding of ocean dynamics and practical application in ocean engineering. In this study, the SWH field in the North Pacific Ocean is generated based on satellite altimeter data. Due to the limitations of a single satellite, such as large orbital spacing and long revisit period, multi-source satellite data are fused to obtain more wave information. The effect of the number of satellites on the fusion results shows that increasing the orbital observations can improve the fusion accuracy, especially for large wave processes. On this basis, an adaptive temporal resolution fusion method is proposed to further improve the fusion effect. This method takes into account the spatiotemporal variation of the wave field in the fusion process, especially the rapid and significant change of SWH. According to the change characteristics of normal and large waves, the temporal resolution can be adjusted flexibly and autonomously to ensure fusion efficiency and accuracy. In particular, this adaptive adjustment can significantly improve the peak underestimation of large waves. Meanwhile, the fusion influence of SWHs in large wave processes on adjacent small SWHs is reduced to avoid over-fusion. The comparison between the buoy observation and fused SWH shows that this method can be used for fusion, especially for capturing peak SWHs during large wave processes. It may allow for comprehensive monitoring and understanding of ocean waves during extreme conditions, providing important support for disaster prevention and mitigation.