To swiftly and efficiently monitor and assess the dynamics of flood disasters under emergency conditions, this study introduces a flood disaster emergency monitoring model based on China’s Gaofen-3 satellite time-series data. This model offers a rapid and effective method for pre-disaster breach warnings, disaster response, and post-disaster loss assessment. In response to the imminent threat posed by the Tuanzhou Embankment breach on July 5, 2024, we conducted emergency remotely-sensed monitoring by using daily image time series data before and after the breach. According to water body extraction and changes detected before and after flooding, we found that the water area in farmlands surrounding the breach experienced a significant increase the day before the dike burst. From 10 a.m. on July 4, 2024, to 11 a.m. on July 5, 2024, the embankment underwent evident seepage process. By the morning of July 6, 2024, the Tuanzhou Embankment was almost entirely submerged, with only the rooftops of houses along the main road remaining above water. From July 8th to 15th, the water gradually receded. The findings indicate that Gaofen-3 data can help effectively monitor the entire disaster evolution process at high spatial and temporal resolutions before, during, and after dike breach, providing crucial data support for pre-disaster early warning, emergency rescue, and post-disaster loss assessment.