Abstract: The thickness, crack, pore and porosity of high-temperature ceramic thermal barrier coatings are the key references for evaluating the thermal barrier properties of coatings. In this paper, the three-layer thermal barrier coatings are taken as the research object, and the morphology, thickness, pore and porosity of thermal barrier coatings are studied from two-dimensional and three-dimensional perspectives with 3D X-ray microscopy and scanning electron microscope. The secondary electron and backscattered electron scanning analysis of the coating before and after service showed that the coating had a dense self-healing layer structure, and there were nondense defect areas in the inner layer. The three-dimensional images collected by 3D X-ray microscopy show the microstructure information such as cracks and pores in a large scale. Through the gray value analysis, the density and strong oxygen resistance of the self-healing layer were evaluated, and the bonding strength between each functional coating was estimated by comparing the gray value differences of them. The results showed that the image analysis results of the two devices are basically consistent, which provides a feasible tactic for the comprehensive analysis of the microstructure characteristics of high temperature ceramic thermal barrier composite coatings.