The hail detection algorithm(HDA)of the CINRAD is investigated,and design features of algorithm in early(7.0)and advanced editions(10.0)are analyzed.The results show that the thinking of HDA is analogous with that of nowcasting of the rainstorm,and both of them are based on the detection of high reflectivity factor in storm cells.The tentative plan of nowcasting disastrous precipitation(hail and local rainstorm)is first put forward using the hail index(HI)on the basis of different seasons.By means of statistical analysis and research of HI and VIL etc radar products,some basic methods and establishment of algorithm threshold on forecasting disastrous precipitation are summarized in a number of cases,and so as to provide referential messages for forecasters to use the products of the CINRAD.