Laplacian of Gaussian Operator with rotation invariance and sensitive to gravity and magnetic field gradient mutation is isotropic second-order differential operator, which has nothing to do with geological boundary objects trend. By calculating the zero value of the Laplacian of Gaussian Operator, the authors delineated the boundary in potential field and extracted geological body distribution, characteristics of fracture structure plane distribution and other geological information. The application of numerical experiments to airborne gravity data indicates that the method can effectively determine the gravity and magnetic source boundaries with higher resolution and accurate positioning. Especially for the multi-sources overlapping geological structure with different depths, different scales and different attitudes, the method can clearly detect the boundaries of weak anomalies with relatively smooth gradient and adjacent local anomalies with superimposed interference. It also can provide more details for further improvement of fine interpretation of the gravity and magnetic local anomalies, and has certain significance for detecting the geological boundaries, devising tectonic units, and determining the fracture zone and the trend of geological structure. All this will facilitate the integrated interpretation.