Abstract: To address the issues that existing stabilizers face, such as side reactions with isocyanates and potential carcinogenicity, a novel branched substituted phenolic stabilizer suitable for nitrate ester-containing propellants was designed. A trimethylolpropane triglycidyl ether-tris(2,6-dimethoxyphenol) ring-opening adduct (AH3) was synthesized from trimethylolpropane triglycidyl ether and 2,6-dimethoxyphenol as main raw materials in a mixed solvent of water and ethanol using potassium carbonate as catalyst. Its molecular structure was characterized by ¹H nuclear magnetic resonance (¹H NMR) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy. The compatibility of AH3 (at an addition level of 1%) with a poly(ethylene glycol)(PEG)/nitroglycerin (NG) /1,2,4-butanetriol trinitrate (BTTN) film was investigated by differential scanning calorimetry (DSC). The color-change times in the Abel test for PEG/NG/BTTN films containing 1% AH3 and 1% MNA, respectively, after heating at 70 ℃ for 14 days were measured. The results show that the molecular structure of the synthesized AH3 is consistent with the designed structure, with a purity of 97.2%. AH3 exhibits good compatibility with the PEG/NG/BTTN components. The Abel test color-change time exceeds 60 min, indicating AH3 can effectively capture nitrogen oxides released from nitrate ester decomposition and its potential value for further research.