Abstract: A comparative analysis of all the proposed solutions of flux leakage detection for tubing/casing, identifying both the advantages, disadvantages and application scope of each individual solution.To meet the requirement for inspection of tubing and casing with different sizes, it is proposed to use strip type detection shoe to detect transversal defects.And also proposed are one special time division multiplex(TDM) method for acquisition of large amount of array Hall signals, and one design solution of the comprehensive inspection system.