Abstract: The measured gravity anomaly is a superimposed field composed of a regional field and a local field, whose characteristics is complex shape and various amplitude changes. In order to complete the geological task better, it is necessary to separate the regional field and the local field. Based on the the measured gravity anomalies, this paper studies the relationship separately between the elevation and free-air gravity anomaly, simple bouguer gravity anomaly, bouguer gravity anomaly. By the way of mathematical statistics to perform regression analysis, the regional field (background field) and the local field (remaining field) are separated which improves the credibility of the interpretation results of gravity data and provides basic services for analyzing and solving geological tasks.