The turbine blade is one of the crucial components in advanced aeroengines. It is of importance to apply the thermal barrier coating (TBC) to the turbine blade in a bid to enhance its high temperature resistance and corrosion resistance performance. However, defects involving wallthinning and delamination considerably decrease the protective effect of inservice TBC, which significantly influence the safety of turbine blades and aeroengines. This paper intensively investigates the technique for quantitative NDE of TBC which is subject to wallthinning defects in micrometers. It has been found that highfrequency eddy current technique in conjunction with the inverse model is applicable and effective for NDE of TBC. The establishment of eddy current impedance signal  the thickness of TC and the thickness of BC the analytical equations and combining with the inverse algorithm and the pickup coil impedance signal, the simultaneous solving the thickness of TC and BC. And then add them up, getting the thickness of TBC. To validate the computational results, by scanning electron microscope (SEM) to measure the true thickness of sample thermal barrier coatings. The results show that this method can achieve efficient quantitative assessment of thermal barrier coating of turbine blades with accuracy over 90%.