Relying on its advantages of flexible combination of casing pipes, the structure of Aviation Metallic Casing Pipes (AMCPs) is widely applied to the important equipment in the field of aviation and spaceflight, enhancing the safety and stability of aviation pipeline service. In order to further guarantee the longterm safety and structural integrity, it is indispensable to periodically inspect AMCPs and evaluate defects via effective Nondestructive Evaluation (NDE) techniques. In light of this, this paper intensively explores the testing mechanism and probe optimization of Remote Field Pulsed Eddy Current (RFPEC) evaluation of a typical AMCPs structure which includes stainlesssteel and carbonsteel casing pipes. The distributions of Poynting vectors and magnetic field within the internal and external regions of AMCPs are analyzed by fast finiteelement modeling. Based on this, a method for localization of remote field is proposed. Following this, the Electromagnetic Shielding Structure (EMSS) for probe optimization is intensively investigated. Parallel to the simulations, a series of experiments for evaluation of wallthinning defects in ACMPs are carried out by using the builtup testing system. The recognition method is valid.