Skin photoaging, a degenerative process caused by ultraviolet radiation, plays a pivotal role in clinical diagnosis and anti-aging research. This paper systematically reviews the evolution of skin photoaging assessment tools, tracing their development from traditional clinical scoring systems to modern imaging technologies, biomarker detection, and AI-assisted analysis. It provides detailed categorization, application scenarios, and comparative evaluations of these methodologies. The study reveals that single-assessment tools have inherent limitations, while multimodal integrated evaluation has emerged as the prevailing approach. Future efforts should focus on integrating molecular biology and AI technologies to establish a more precise photoaging assessment framework.