Abstract: Pulsed magnetic flux leakage(PMFL) technology shows potential advantages in the detection of corrosion, cracks and other defects of ferromagnetic plates or pipeline. A PMFL sensor with new structure was proposed based on the simulation for a variety of different structure sensors. It reduced the magnetic field compression of the background noise to the magnetic flux leakage signal and improved the information accuracy of defects. It was suitable for detecting defects under insulating layer or coating layer. The new structure sensor was developed and the standard samples were tested using it. The experiments validated the optimization of configuration and effectiveness of the new sensor.