Aiming at the problem of low strain tolerance present in Ba(Mg1/3Ta2/3)O3(BMT) thermal barrier coating prepared by conventional atmospheric plasma spraying, based on suspension plasma spraying (SPS), a BMT suspension with different composition was prepared by mechanical ball grinding using ethanol as the dispersion medium and polyacrylic acid (PAA), polyethyleneimine (PEI), and polyethylene glycol (PEG) as dispersants. The dispersion behavior of BMT suspension was studied by using the gravity sedimentation observation method, UV-Vis spectrophotometer, and Zeta potentiometer, and the effects of dispersant types and contents on the stability of BMT suspension were analyzed. The BMT coating was deposited using SPS, and the phase structure, surface morphology, and cross-section microstructure of the BMT coating were characterized and analyzed. The results show that the adsorption of the dispersant PEI on the surface of the BMT particles could improve their Zeta potential, enhance the repulsive force between particles, and provide a steric hindrance, which led to a better dispersion for BMT suspension than PAA and PEG. In addition, the BMT suspension with PEI had a low viscosity (1.5-2 mPa·s), making it appropriate for SPS. The coating prepared by SPS essentially preserved the BMT phase structure, and showed a clear columnar-crystal microstructure. With the increase of the solid content in the suspension, the deposition efficiency of the BMT coating increased, and the volume of columnar crystals formed was larger, which conforms to the microstructural characteristics of high strain tolerance coatings.