Abstract:We research how to obtain the optimal weight value in flow gravity observation data processing, which can be used to calculate gravity value. In the processing, we use the least-square method to solve the overdetermined equations consisting of the weight coefficient and the observations. The results show that the accuracy of the point value derived from the equal-weight method is not good enough. However, it contains more information for gravity anomaly seismic analysis and prediction. Although the accuracy of the point value solved by the unequal-weight method is better than the equal-weight method, it contains less information which may inhibit gravity anomaly seismic analysis and prediction. Finally, the results obtained from the least-square method not only have higher accuracy of the point value, but also is the best among the three methods, which can be used to analyze and predict the earthquakes with magnitude large than MS4.0.