Abstract: The high temperature working environment of aeroengine and gas turbine will cause irreversible damage to the hot metal parts. Thermal barrier coatings can withstand aggressive conditions of high temperatures and pressures, which ensures safety and reliability in use of metal parts. Two forms of hollow YSZ raw material particles in the plasma flame flow during the preparation of TBCs by plasma spraying process, namely fully molten droplets and hollow droplets are the subjects of this paper. Based on the ABAQUS/EXPLICIT coupled Eulerian-Lagrangian (CEL) finite element method, this paper gave an empirical formula of dynamic viscosity varying with temperature in response to the lack of phase transformation model in CEL method, which causes the distortion of droplet spreading morphology. Besides, considering the influence of air, a 2.5D CEL finite element model of "TPF/FSI" was proposed, the process of solidification and air entrapment of the droplet impacting substrate was simulated, and the mechanism of great difference between the two droplet spreading morphologies was revealed, which has guiding significance for the preparation of TBCs with better thermal insulation performance.