Using the method of normalized full gradient of gravity anomaly and its phase in the wavenumber domain, this paper studied four typical staircase models, discussed the relationship between the GH field contour and the phase curve, processed the high precision gravity data on the basis of the measurements made along the Danqinghe forestDaotaiqiao section (called DB4 for short) on the periphery of Daqing prospecting area and recognized eight fractures. Through a comparison with the inversion results from the magnetotelluric method, the authors investigated YilanYitong fractures, Mudanjiang fractures and the west edge fracture of Boli Basin, and also summed up the gravity and magnetotelluric data to perform structural division of this section and make geological interpretation. As fractures are closely related to the formation of source depressions and the entrapment of oil and gas, the authors probed into the main fractures in the DB4 section and their characteristics so as to provide the geophysical evidence for locating the promising oil and gas districts on the periphery of Daqing prospecting area.