本文研究了强震前的地震活动前兆。为定量描述这组前兆,我们研究了一组自相似地震活动函数。在此基础上进行了自相似地震活动特征的提取。然后利用直方图法对每一特征作了特征选择,如此共选取了21个特征。这些特征反映了强震活动水平增高,地震活化,地震活动偏离正常值及b值异常等地震活动前兆现象。 This paper studies the precursory seismic activity before strong earthquakes. To quantitatively describe this set of precursors, we studied a set of self-similar seismic activity functions. Based on this, the feature extraction of self-similar seismic activity was carried out. And then use the histogram to make a feature selection for each feature, so a total of 21 features selected. These characteristics reflect the seismic precursory phenomena such as the increase of the activity level of strong earthquakes, the activation of the earthquakes, the deviations of normal seismic activity from the normal values ​​of b and the abnormal b values.