[Objective] Taking Wangjiang County, Anqing City of Anhui Province as the research area, this study designed twenty year flood disaster in order to provide a scientific basis for the application of remote sensing and geographic information system (GIS) in disaster analysis.[Methods] Using remote sensing and GIS technology, land use was supervised and classified based on remote sensing and DEM data base. The submerged area was calculated by seed spread algorithm, calculation, and the proportion of each type of land use in the submerged area was obtained. A flood disaster assessment model was established, and the flood disaster in 20 years was simulated and analyzed by analogy method.[Results] With the influence of the flood disaster in Wangjiang County in 20 years, the affected area was more than 50% of the total area, and the affected population was more than 90%. Using submerged data combined with cases data, the case could be characterized as large flood disaster. By analogy with typhoon "Pearl" with similar evaluation coefficients, disaster relief and rescue measures were designed with test data.[Conclusion] The combination of remote sensing and GIS technology provides a platform for flood design. By using submerge data, the disaster level can be evaluated as soon as possible. Through analogy analysis with the same level of disaster and combining with the actual situation, the disaster relief measures can be drawn up quickly and accurately, and the case can be assessed as a case for reverence.