Aimed at the problems that the signals of traditional remote field eddy current are weak, and the detection sensitivity is low, and how to realize the suppression of the magnetic field in the remote field eddy current is a key problem to improve the detection ability, this paper designs some sensors with different shield structure from the perspective of restraining direct coupling component of magnetic field, analyzes the effect of shield with different materials, and compares the defects, detection sensitivity and the capability of detecting large thick flat geometry. The results show that the sensor with the connected magnetic circuit based on high magnetic shield has a good ability in restraining as for the direct coupling component, and can shorten transient length, can narrow the distances between the excitation and the detection coil, and can improve the sensitivity in detecting defects. And its detection depth can be extended to 25mm as for nonmagnetic plate.