Mice were administered a selenium-rich Agaricus blazei Murill (Se-AbM) polysaccharides and tea polyphenol compound solution for prevention and treatment. Following exposure to 2 Gy of infrared radiation, peripheral blood counts of white blood cells, red blood cells, and platelets were assessed, along with serum levels of apoptosis-related factors Fas and Fas ligand, inflammatory factors interferon-gamma and tumor necrosis factor-alpha, immune-related factors interleukin-3 and interleukin-6, and indicators of oxidative stress, including malondialdehyde, superoxide dismutase, and glutathione. The results showed significant differences in these indicators between the Se-AbM-treated group and the model group, suggesting that Se-AbM may inhibit apoptosis, enhance the clearance of free radicals in the body, improve antioxidant capacity, and provide a significant protective effect against radiation-induced immune damage.