Synovial joints, such as knee, temporomandibular, and spinal joints, play a key role in human movement and postural maintenance. Biological research has focused on understanding their developmental process and disease mechanisms. In recent years, the rapid development of single-cell transcriptome sequencing has provided a powerful tool for revealing the mysteries of synovial joints. Single-cell transcriptome sequencing can accurately capture the gene expression profile of each cell, thereby revealing the heterogeneity and interactions of different cell types in synovial joints. During joint development, this technique contributes to elucidating the molecular mechanisms of joint formation, cartilage differentiation, and synovial tissue construction. In terms of joint disease research, single-cell sequencing technology has been applied to the molecular pathology studies of various joint diseases such as osteoarthritis, rheumatoid arthritis, and intervertebral disk degeneration, providing new perspectives and strategies for early diagnosis, accurate treatment, and prognosis assessment of diseases.