Abstract: By studying and analyzing the characteristics of unusual changes of the pre-earthquake groundwater level in deep well in the past 30 years in Kaiyuan,the author has decided to use mathematic methods to process the data by filtering waves,and thus to further extract unusual long-term and short-term indexes of the moderate or strong earthquake attacked in and near Yunnan.Additionally,the paper also involves discussions on the micro dynamic changes of deep well groundwater level before earthquakes.