In the past 10 years, the level of heavy metals has sharply increased in the Jiangxigou farm in the Qinghai Lake basin, which has seriously affected the health of Przewalski’s gazelle. Nano-potassium molybdate (nano-K2MoO4), as a new nano-fertilizer, has been applied in agriculture. To study the effect of applying different levels of nano-K2MoO4 fertilization (8 kg/hm2, group I; 9 kg/hm2, group II; 10 kg/hm2, group III) on preventing heavy metal toxicity in Przewalski’s gazelle. The samples of soil, forage, and animal tissues were collected for testing heavy metals and mineral contents, oxidative stress, and blood indexes. The empirical findings showed that the contents of selenium (Se) and copper (Cu) in the tested forage were significantly higher than those in the control group (p<0.01). The levels of Cu and lead (Pb) in the blood and liver of the tested Przewalski’s gazelles were remarkably higher than those in the control animals (p < 0.01), but the levels of molybdenum (Mo) and Pb were remarkably lower than those in the control animals (p < 0.01). The levels of hemoglobin (Hb), platelets (PLT), and red blood cells (RBC) in the tested Przewalski’s gazelles were remarkably higher than those in the control animals (p<0.01). The enzymatic activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC) in the serum of the tested Przewalski’s gazelles exhibited a significant increase in comparison to the control animals (p<0.01), but the content of malondialdehyde (MDA) was lower than that in the control animals (p<0.01). In summary, the application of nano-K2MoO4 not only significantly improved the antioxidant capacity and alleviated effectively the anemia symptoms of Przewalski’s gazelle, but also reduced the heavy-metal toxicity of Przewalski’s gazelle in the fertilization areas.