Plasma sprayed Al2O3/TiO2 ceramic coatings have excellent wear resistance and chemical stability. They also have broad application prospects in friction components in various environments. In recent years, the emergencing of nano Al2O3/TiO2 coatings has attracted people’s attention. This article analyzes the microstructure and high-temperature debris morphology of the nanostructured Al2O3–13% TiO2 coating prepared by plasma spraying process. The microstructure of nanostructured aluminum oxide coating was studied, and it was found that the layer presented obvious micro and nano dual structure, and the structure was dense, with good interface bonding. This was because the nanostructured powder particles were fully melted in the spraying process, and the structure in the large particles was preserved. Analysis of the fracture morphology of the coating revealed that the structure was relatively rough, with a morphology similar to “ductile dimples”. There was an equiaxed structure in the fracture surface, and the bonding surface between the single layers of the nano coating was not simply a mechanical overlap between layers, but presented a state similar to mutual fusion.