Abstract: Different effects of two magnetization methods were compared by FEM with no.28 wire rope being as an example. The magnetizer size influence on rope magnetic field and MFL signals was analyzed to obtain correlation curves of MFL axial component which was changing with magnetizer size and hence to obtain the best size of probe for rope detect. A miniature differential Sensor Array was introduced, the performance of the analysis method and sensor were validated by experiments and the experimental result just met the analysis result. The result can be used in magnetic circuit design for improving magnetic effect and testing sensitivity.