Abstract: As the depletion of the ozone layer continues and the utilization of ultraviolet radiation (UVR) expands across various domains, the effect of UVR on human health has garnered increasingly widespread attention. Historically, research on UVR has predominantly focused on its effects on the skin, which, as the largest and outermost organ of the human body, can be exposed directly to UVR or sunlight for long periods of time, leading to sunburn, inflammation, photoimmunosuppression, photoaging, and even skin cancer. Recent research suggests that the biological effects of UVR extend beyond the skin because UVR can modulate various organs and systems within the body through metabolic regulation and other mechanisms. Additionally, UVR affects the eyes, microbiome, cardiovascular, immune systems, and nervous systems. The authors review the effect of UVR on the functions of multiple organs and its mechanism to obtain a comprehensive understanding of the biological effects of UVR.