Testicular radiation injury is a structural and functional abnormality of the testes caused directly or indirectly by radiation, which disrupts spermatogenesis and compromises male fertility. The development of effective preventive and therapeutic interventions is essential because of the high prevalence of this condition in clinical settings and its profound effect on patients′ reproductive health and overall well-being. The concept of "the struggle between vital qi and pathogen" is first seen in the Treatise on Cold Pathogenic Diseases. It denotes the dynamic struggle between vital and pathogenic qi. The occurrence, development, and sequelae of all diseases reflect this ongoing conflict. In this context, this study defines the "vital qi" of the testis as its capacity to generate and preserve the essence of reproduction and to resist damage. The pathogenic qi associated with testicular radiation injury is categorized into two types: ionizing poison and retaining evil. The pathogenesis of testicular radiation damage is delineated into three stages by integrating the characteristics of vital and pathogenic qi: the injury, adhesion, and recovery phases. Based on the theoretical framework advanced by this study, the therapeutic approach for testicular radiation injury should adhere to the fundamental principle of strengthening vital qi and eliminating pathogenic factors. Although the primary focus of treatment should be on strengthening vital qi, it should also be complemented by strategies to eliminate pathogenic influences. This paper aims to provide a novel perspective and strategic approach to the traditional Chinese medicine diagnosis, prevention, and treatment of testicular radiation injury. By elucidating the process of testicular radiation injury and its corresponding treatment principles, it seeks to offer valuable insights for clinical practice.