Abstract: In recent years, detection technology of oil and gas pipelines has been widely used in China and has become a tool essential for integritymanagement of pipeline operators. However, one-dimensional probe–based magnetic flux leakage test equipments can not accuratelydescribe the 3D leakage magnetic field and is likely to cause lack of defect detection accuracy and reliability. In order to improve defectdetection capability and accuracy of measurement, the 3D probe technology is used to restore a true leakage magnetic field so as toaccurately identify and measure pipeline's defects. A static test platform is built to explore the relationship between probe acquisition dataand defect shape and lift off impacts on the data, and a dynamic test platform is built to focus on the research of impacts of speed, liftoff, residual magnetism and other factors on the leakage magnetic field.