Abstract: To provide the scientific basis for inducting the corn production and insurance claims in Huaibei Plain, based on the precipitation data during summer maize’s growth season in Huaibei Plain from 1961 to 2010, this paper disclosed the output effect of ten-days rainfall to maize yield and its key period of time by means of integral regression method, and obtained the climate index about drought and flood in different growth stages as well as the whole period by percentile method of precipitation probability less than 20% and more than 80%, meanwhile, this paper also analyzed the area distribution of drought and flood as well as the maize yield loss and its risk distribution. The results showed that, the ten-days rainfall had more negative effect than positive effect during summer maize’s growth season in Huaibei Plain, the precipitation from tassel appearance to milky of maize had significant effect on maize’s yield, when the drought and flood could cause yield reduction of 12.6% and 16.3% respectively. In Huaibei Plain, the climate index about drought and flood in different corn stages (sowing-seeding stage, seeding-jointing stage, jointing-tassel appearance stage, tassel appearance-maturity stage and the whole period) were that, the total rainfall during the corresponding stage was ≤17.0, ≤50.0, ≤95.0, ≤110.0, ≤370.0 mm and ≥95.0, ≥235.0, ≥265.0, ≥280.0, ≥740.0 mm respectively. There was more flood than drought during maize’s growth season in Huaibei Plain, and the risk had a warp and weft distribution, the relative reduction rate caused by drought and flood in maize’s whole growth stage was -22.4% and -28.9% respectively, and in other stages the relative reduction rate was between -8% and -16%.