This study focuses on bone metastasis of prostate cancer. By analyzing clinical samples and serum samples, it aims to reveal key molecular mechanisms and explore diagnostic and therapeutic targets. The specific goals include: First, identifying molecular markers related to bone metastasis, using high-throughput sequencing and proteomics analysis to screen for differentially expressed genes, proteins or ssDNA sequences; Second, analyzing the functions and mechanisms of key molecules, clarifying their roles in the interaction between tumor cells and the bone microenvironment through cell and animal experiments; Third, evaluating the potential of ssDNA as a new biomarker, studying its binding characteristics and the application value of liquid biopsy.