Magnetic Barkhausen noise (MBN) has found potential applications in detecting fatigue, creep, stress, and hardness in ferromagnetic materials. As a direct carrier for magnetic Barkhausen noise excitation and reception, the characteristic of a sensor determines the quality of the detection results. A design method for a high-spatial-resolution MBN sensor is proposed in this paper. Adding a thin-film shielding layer outside the ferromagnetic core coil (FCC) receiver, this method limits the effective signal receiving area of an MBN sensor to a small local region below the receiver, thereby improving the spatial resolution, testing stability, and damage quantitative evaluation abilities in measurement. Experiments show that equipped with a high-permeability and -conductivity material shield, the diameter of the receiving area of the MBN FCC receiver is reduced from 16–18 mm to 8–10 mm. This means that it can obtain better spatial resolution in images, reduce the background noise and disturbance, and precisely detect MBN signal variation. The proposed method provides a key design method for small-space MBN detection, MBN scanning imaging detection, and MBN sensor array.