Plasma spray-physical vapor deposition (PS-PVD) is a new method for preparing high temperature protective coatings and functional coatings, not only covering plasma spray and electron beam physical vapor deposition processes, but also including customized design and preparation of macro/meso/micro cross-scale structures in coatings. It has been broadly applied in areas such as thermal barrier coatings (TBCs), environmental barrier coatings (EBCs), environmental thermal barrier coatings (TEBCs), oxygen permeable membranes, fuel cells, and solar cell electrode films. Especially in the field of aero-engine and gas turbine protective coatings, it is regarded as a new direction for the development of high-performance TBCs/EBCs preparation technology. The whole process of PS-PVD in expansion flow of plasma jet, material rapid heating gasification ionization and long-distance multi-mode transport deposition was compared and analyzed and the PS-PVD principle and equipment system were introduced. For the goal of rapid non-destructive testing of plasma jet parameters, a detection and diagnostic equipment system was established based on spectroscopy (OES) plasma jet and material property, and quantitative characterization and accurate diagnostic methods for jet and material property parameters were developed. According to the detection results of electron number density and other detection results, the plasma temperature distribution law was further calculated and analyzed. Based on the results of jet and material detection, the multi-phase transition behavior in the plasma jet of powder material was studied, and the process control parameter set for controlling the multi-phase transition of the deposition unit was summarized. The establishment of hardware platforms and characterization detection methods provides a solid theoretical basis and necessary conditional support for constructing PS-PVD theory and developing new high-performance thermal protective coatings.