A double rare-earth (Yb/Y) co-doped SrZrO 3 [Sr 1.0 (Zr 0.9 Yb 0.05 Y 0.05 )O 2.95 ] thermal barrier coating was prepared via suspension plasma spraying (SPS). The rare-earth nitrates [Zr(NO 3 ) 4 ·5H 2 O, Sr(NO 3 ) 2 , Yb(NO 3 ) 3 ·6H 2 O, Y(NO 3 ) 3 ·6H 2 O] and NH 4 (C 2 O 4 ) 2 ·H 2 O were used to prepare the precursor suspension by co-precipitation. The thermal decomposition and crystallization of the precursor suspension powders calcined at 1200 °C were characterized with X-ray diffraction and a synchronous thermal analyzer coupled with quadrupole mass spectrometry . Zr 2 (C 2 O 4 ) 2 (OH) 4 decomposed into Zr(C 2 O 4 ) 2 , ZrO 2, and H 2 O initially, followed by the decomposition of Zr(CO 3 ) 2 into ZrO 2 . The SrC 2 O 4 precursor decomposed into SrCO 3 and SrO consecutively. The ZrO 2 reacted with SrO (Yb 2 O 3 , Y 2 O 3 ) to generate the Yb/Y co-doped SrZrO 3 . And the Yb/Y co-doped SrZrO 3 coating with a columnar crystal structure was prepared by SPS, which was analyzed with scanning electron microscopy, an inductively coupled plasma atomic emission spectrometer, and a laser flash analyzer. The thermal conductivity of the as-prepared coating was 1.77 W·m −1 ·K −1 at 1000 °C, which was more than 19% lower than that of the SPS SrZrO 3 coating. • The precursor suspension was prepared by co-precipitation using Zr(NO 3 ) 4 ·5H 2 O, Sr(NO 3 ) 2 , Yb(NO 3 ) 3 ·6H 2 O, Y(NO 3 ) 3 ·6H 2 O and NH 4 (C 2 O 4 ) 2 ·H 2 O. • The phase evolution of the precursor suspension was investigated. • The Yb/Y co-doped SrZrO 3 coating was prepared by suspension plasma spray using the prepared precursor suspension. • The Yb/Y co-doped SrZrO 3 coating has a low thermal conductivity of 1.77 W·m -1 ·K -1 at 1000 °C compared to SrZrO 3 coating.