Abstract: As one of the piping structures, the double-casing pipe (DCP) consisting of the inner and outer pipes in different materials is usually employed in such engineering fields as petroleum, chemical and aerospace, etc. Corrosion can be found in in-service DCPs, and it severely undermines the structural integrity of the DCP. Consequently, it is vital to effectively inspect DCPs via in-situ nondestructive evaluation (NDE) techniques. In this paper, near- and remote-field pulsed eddy current hybrid testing technique (NRPEC) is intensively investigated for the evalution of hidden corrosion in the stainless steel-casing iron DCP. The correlations of the testing signal and its features with the parameters of the external wall-thinning defect are analysed through simulations. Based on this, the algorithms for classification and quantitatively evaluation of the defect are proposed. In parallel, an NRPEC system is built up for experimental investigation. The validity of NRPEC and proposed algorithms is identified via experiments.