Ground Penetrating Radar (GPR) is an effective means of detecting underground structures, which can be applied to drilling engineering to detect geo-bodies in the borehole. Although the GPR image can reflect the type and distribution of the geo-bodies to some extent, it is still a research hotspot to identify the geological body based on the detection results. This paper analyzes the imaging principle of single-hole reflection survey and obtains the reason for the fringes with different intensities and directions in the GPR image. Changes in the geo-bodies cause changes in the reflected energy of the electromagnetic waves, resulting in the formation of these fringes. And the possibility of characterizing these fringes by the Curvelet transform is analyzed. Then, the change in the reflected energy of the electromagnetic wave is equivalently substituted by the change in the energy of the Curvelet coefficients of the fringes, from which the three-dimensional energy change trend figure is obtained. The identification results from the energy change figure show that except for the difficulty to identify structural planes with specific orientations and fissures with soil-filled, other geo-bodies can be effectively identified.