Ionosphere TEC abnormal value extraction method and system

The invention discloses an ionosphere TEC abnormal value extraction method and system, and the method comprises the steps of selecting the TEC values at the same moment in the first 27 days from a pre-constructed data set to form a group of time series data, constructing a time-delay matrix, extracting the change trend of the TEC values in the 27 days through employing a principal component analysis method, then calculating a reference background TEC lower bound value and a reference background TEC upper bound value by using a quartile distance method; collecting the ionosphere TEC time sequence data in a current time range and carrying out equalization processing on the ionosphere TEC time sequence data; comparing each TEC value in the time sequence after equalization processing with the calculated reference background TEC lower bound value and the reference background TEC upper bound value, and if the TEC values are smaller than the reference background TEC lower bound value, determining that the TEC values