In order to get an estimation method for the effective precipitation in Huaibei plain during the crop growth period, an experiment lasting for three years was designed based on three levels and six processing according to the survey of the effective precipitation. In the experiment, wheat and summer maize were taken as objective, and the area of the six set measurement tubes of the earth lysimeter were 2.0 m² and 4.0 m² whose buried depth under control of the groundwater are 1.0 m, 1.5 m and 2.0 m in Wudaogou Key Laboratory of Water Resources. The soil sample is lime concretion black soil. Based on a long series document, the analysis of the effective precipitation and the effective precipitation coefficient in different groundwater burying depth (1.0 m, 1.5 m and 2.0 m)were gotten at three kinds of typical annuals (5.1％, 48.7％ and 94.9％), and the effective precipitation at different time, that is, month, quaternary and year was estimated.