Radiation-induced intestinal injury is caused by high dose of radiation in the abdomen and pelvis. The disease is characterized by complicated pathological mechanisms and poses significant challenges to clinical treatment, seriously affecting the quality of life and health of patients. Current treatments in modern medicine offer limited efficacy and are often associated with adverse side effects. Traditional Chinese medicine monomers inhibit inflammatory factors (e.g., tumor necrosis factor-α and interleukin-1β) and regulate the antioxidant enzyme system (e.g., improving the activity of superoxide dismutase) to effectively reduce the symptoms of radiation-induced intestinal injury with minimal side effects. Through targeted delivery of nanoparticles, nanotechnology can accurately deliver the active ingredients of traditional Chinese medicine to damaged intestinal tissues, thus improving their bioavailability and therapeutic effects. This paper reviews the mechanisms of Chinese medicine monomers in the prevention and treatment of radiation-induced intestinal injury and the application of nanotechnology for enhanced efficiency. The paper also discusses the clinical potential of these approaches. These results provide a reference for future research and clinical practice.