In conclusion, these results demonstrated that miR‐92a‐1‐5p derived from PCa exosomes disrupts bone homeostasis, promotes osteoclast differentiation, inhibits osteoblast differentiation, and promotes tumor bone metastasis in PCa; moreover, our findings suggest the following underlying mechanism: miR‐92a‐1‐5p and MDA PCa exosomes containing miR‐92a‐1‐5p target COL1A1 and accelerate bone ECM degradation. The gene discussed is COL1A1; the disease is posterior cortical atrophy.