Because of the rigorous working environment, Subsurface Material Degradation (SMD) occurs in the stratified metallic structures which are extensively employed in industries such as aerospace and energy fields. This directly influences the angle operation of crucial components in the large-scale complex apparatus. This paper investigates a new Lift-off Intersection Point (LOI) via theoretical study of Pulsed Eddy Current Testing (PECT). Following the analysis of the forward problem of the new LOI, a method for evaluation of SMD in stratified metallic structures is proposed. Through experiments the proposed method displays some advantages. By using it the sensitivity of PECT based on the new LOI to subsurface material degradation is higher than that of the traditional-LOI based PECT, which benefits the quantitative evaluation of subsurface material degradation occurred within the practical stratified metallic structures.