Carotenoids， valued for their exceptional free radical scavenging properties and low biological toxicity， were systematically investigated as potential stabilizers for propellants. A comprehensive evaluation strategy， incorporating differential thermal analysis （DTA）， methyl violet test strips， isothermal thermogravimetry， vacuum stability testing， and accelerating rate calorimetry （ARC）， was employed to assess their stabilizing effects. Four representative carotenoids-lycopene， β-carotene， xanthophyll， and astaxanthin， were examined for their stabilization performance in nitrocellulose （NC） and absorptive composition systems. All tested carotenoids demonstrated superior thermal stability compared to conventional stabilizers. Notably， astaxanthin exhibited the most significant enhancement： it prolonged the methyl violet discoloration time of NC by 40 min， reducing mass loss by 17.90%， decreased the maximum adiabatic decomposition temperature rise rate by 0.134 ℃·min^-1， and lowered gas pressure release per unit mass by 12.0 kPa. In absorptive compositions， it extended the methyl violet discoloration time by 34 min while reducing mass loss by 14.18%. Free radical scavenging tests and intermediate structural analyses revealed the underlying stabilization mechanism： carotenoids effectively suppress autocatalytic decomposition via nitrogen-oxygen free radical capture， achieving nearly 90% scavenging efficiency at 8 mmol·L^-1. Additionally， secondary derivatives formed during carotenoid degradation were free of nitrosamine groups， significantly reducing toxicological concerns.