Oxidative stress is associated with many diseases and has been found to induce DNA damage and cellular senescence. Numerous evidences support the detrimental effects of oxidative stress or cellular senescence on skeletal homeostasis. N-acetylcysteine (NAC) is a powerful antioxidant. However, it is unclear whether NAC can suppress orchiectomy (ORX)-induced osteoporosis by inhibiting oxidative stress and osteocyte senescence. In this study, ORX mice were supplemented with/without NAC, and were compared with each other and with sham-operated mice. Our results showed that NAC could prevent ORX-induced osteoporosis by inhibiting oxidative stress, DNA damage, osteocyte senescence and senescence-associated secretory phenotype (SASP), subsequently stimulating osteoblastic bone formation and inhibiting osteoclastic bone resorption. The results from this study suggest that NAC could be considered as a potential therapeutic agent for prevention and treatment of osteoporosis caused by testosterone deficiency.