Gut microbes are known as the body's second gene pool. Symbiotic intestinal bacteria play a major role in maintaining balance in humans. Bad eating habits, antibiotic abuse, diseases, and a poor living environment have a negative effect on intestinal flora. Abnormal intestinal microbes are prone to cause a variety of diseases, affecting life expectancy and long-term quality of life, especially in older people. Several recent studies have found a close association between intestinal microorganisms and osteoporosis. The potential mechanism of intestinal flora affecting bone formation or destruction by mediating nitric oxide, the immune and endocrine systems, and other factors is briefly described in this review. All of these factors may be responsible for the intestinal flora that causes osteoporosis. Studying the relationship between intestinal flora and bone health not only provides new ideas for studying the role of intestinal microorganism in osteoporosis, but also provides a new therapeutic direction for clinically refractory osteoporosis. Study of the relationship between intestinal microbiota and osteoporosis is important for maintaining bone health and minimizing osteoporosis.