Abstract: Six mini reservoirs in Jiangsu province were taken as the examples here to evaluate the height of dams, adopting instantaneous unit line to ascertain design flood in different design storm. It has been carried out to simulate seepage, sliding and earthquake resistance of dam by means of Canadian software Geo-Slope in different design storm .Hereby, it can take conclusion about safety suggestions and measures after analying the main safety perils by taking the reservoirs as examples.