A circular survey for 3D GPR using the linearly polarized antenna is proposed to detect and map the hidden cylinders. The backscattering signal from cylinders may strongly depend on the orientation of the cylinder relative to the antenna. The circular survey can conform to the optimal measuring condition that the long axis of the bow-tie antenna oriented is parallel to the long axis of the cylinders, and always obtain the strongest reflected signal from the cylinders. A regular survey and a circular survey using 3D GPR were carried out in the sand pit, and two crossing metal pipes were buried in dry sand as the targets. The compare results show the advantage and potential of the circular survey to detect the cylinders with the different orientations simultaneously. The fusion of the migrated result and the locations of the detected hyperbolic apices can provide more accurate mapping result of two pipes in accordance with the true scene.