A heavy rainfall occurred on July 3, 2006 in Huanghuai region has been analyzed and simulated, making use of surface and aerological data and wind data of automatically stations per-hour. The results show that the instability energy of both sides of shear line plays an important role in forming a short-time rain; the heavy rain is generated by several meso-β-scale cyclones moving eastward directly; under the suitable background of large-scale circulation, we can use NWP products to anticipate when the rain effects us; with the wide range of satellite images, the strong detectability of radar and the high flexibility of automatical stations, we can make a further step in the forecast of heavy rain to reduce its economic losses.