Astragali radix, a traditional Chinese medicine, is widely used for its antioxidant properties. This review discusses the active components in Astragali radix, including polysaccharides, saponins, and flavonoids, which exhibit antioxidant effects. These compounds help prevent and control diseases caused by oxidative stress. The study summarizes the content, bioavailability, and antioxidant mechanisms of these components, providing insights for clinical applications and the development of new antioxidants. The bioavailability of Astragali radix extracts and their constituents was studied in animals, showing varying levels of absorption and distribution. The antioxidant mechanisms of Astragali radix involve scavenging free radicals, enhancing antioxidant enzyme activities, inhibiting oxidase activities, inhibiting lipid peroxidation, and chelating metal ions. These mechanisms help reduce oxidative stress and protect against various diseases. The study also explores the molecular pathways involved, such as the Keap1/Nrf2, PI3K/Akt, NF-κB, and AMPK signaling pathways, which are crucial for the antioxidant effects of Astragali radix. Overall, Astragali radix and its components show significant antioxidant activity, contributing to the prevention and treatment of oxidative stress-related diseases.Astragali radix, a traditional Chinese medicine, is widely used for its antioxidant properties. This review discusses the active components in Astragali radix, including polysaccharides, saponins, and flavonoids, which exhibit antioxidant effects. These compounds help prevent and control diseases caused by oxidative stress. The study summarizes the content, bioavailability, and antioxidant mechanisms of these components, providing insights for clinical applications and the development of new antioxidants. The bioavailability of Astragali radix extracts and their constituents was studied in animals, showing varying levels of absorption and distribution. The antioxidant mechanisms of Astragali radix involve scavenging free radicals, enhancing antioxidant enzyme activities, inhibiting oxidase activities, inhibiting lipid peroxidation, and chelating metal ions. These mechanisms help reduce oxidative stress and protect against various diseases. The study also explores the molecular pathways involved, such as the Keap1/Nrf2, PI3K/Akt, NF-κB, and AMPK signaling pathways, which are crucial for the antioxidant effects of Astragali radix. Overall, Astragali radix and its components show significant antioxidant activity, contributing to the prevention and treatment of oxidative stress-related diseases.