Abstract: In order to accurately detect a variety of buried pipelines underground, a pipeline detection system based on geomagnetic imaging was proposed. The system compares intensity of pulse signals collected from vertical component of surface magnetic field with intensity of pulse signals collected from vertical component of magnetic field above surface in homogeneous stratum with isotropic medium, and uses the compared data to form three-dimensional images which can reflect the distribution of pulse signal's strength on top of measured region, so as to judge the nature of underground medium. The experiment result showed that values of MAPE detected by the system for underground known pipeline and unknown pipeline are 2.66% and 3.33% separately, and the accuracy of the same detection is improved. The system is good for all kinds of detection of underground pipelines.