中文摘要：

从外磁场作用下铁磁材料内部磁畴结构变化尤其是材料存在缺陷时缺陷两侧磁畴以及磁畴壁的变化分析以及畴壁能量计算出发，得出当材料中存在缺陷时，由于缺陷对畴壁形成钉扎。使得缺陷两侧形成反向势垒，阻碍了畴壁运动，在缺陷边缘附近形成微磁固定结点，微磁结点内磁化方向的变化决定了缺陷区的泄漏微磁场特性，由于微磁固定结点内磁化强度的法向分量不连续，缺陷区形成泄漏微磁场，泄漏微磁场的奇异特征包含了缺陷信息，通过检测这个泄漏场信息，可以实现微磁缺陷检测。

英文摘要：

The change included the domain structure inside the ferromagnetic materials and two side of the defect and the energy of the domain walls were analyzed. It can be concluded that the defect in the ferromagnetic materials can fix the domain wall, the reverse potential wall in the side of the defect blocks the movement of the domain walls, then the micromagnetic fixed knot comes into being around the defect. The direction of the magnetization whose normal component is discontinuous in the micromagnetic fixed knot decides the character of the flux magnetic field which contains the information of the defect, by testing this flux magnetic field , we can realize the defect testing.