Abstract: In view of the high passability requirements of small caliber pipelines for magnetic flux leakage internal detection equipment, a floating magnetization device is designed to adjust the movement attitude of the detector in the pipeline on the basis of meeting the excitation parameters of the magnetic flux leakage internal detection, and hence higher pass ability can be achieved. The passing performance of the ADAMS dynamic analysis software calculation device under different working conditions initially verified the rationality of the scheme, and provided technical support for the development of small diameter pipeline life prediction and scientific management.