Abstract: This paper summarizes the experience in how to judge hydrochemical anomalies, how to make combinational analysis of anomalies.how to determine the three elements of the earthquake and how to propose prediction opinions hefroe Datong eortlquake.As the practical research result of hydrochemical analysis and prediction method of earthquakes was introduced, we made a relatively good thort-term and imminent prediction before the earthquake in the case of limited data.This indicates the previous practical research result is effective.