当前漏磁检测技术对铁磁构件裂纹缺陷检测的理论研究多侧重于矩形缺陷，而实际产生的裂纹形状非常复杂，对其所形成的漏磁场会造成不同的影响，增加对裂纹缺陷评定的难度。针对该问题，对裂纹形状分类，以麦克斯韦方程组为理论基础，建立了裂纹缺陷检测模型，对不同形状裂纹漏磁场进行有限元仿真分析，得出了不同形状裂纹在不同深度、宽度条件下漏磁场的变化情况，通过漏磁场分量的变化可以实现对裂纹缺陷的评定，为实际的裂纹检测提供一定的参考依据。

Magnetic flux leakage inspection technology focused on rectangular defects for the theoretical study of the ferromagnetic crack defect detection in present. However, crack shapes presented in practice are very complicate. Complex shape has influence on its forming leakage magnetic field. It also increases the difficulty of evaluation for the crack defect. According to the problem, the paper classifies the crack shape, and the method is based on the Maxwell equations. Crack defect detection model is established. Finally, the leakage magnetic field of different shape cracks is analyzed by finite element simulation. It is concluded from analysis that the leakage magnetic field of different shape cracks shows different change with different depth and width. The defect assessment of crack is realized through the change of leakage magnetic field. The result can provide effective reference data for crack detection in engineering practice.