With the increasing demand for oral aesthetics in society, tooth whitening technology has become a research hotspot in the field of oral medical cosmetology. In recent years, the cold light whitening technology has been widely used in clinical practice due to its convenient operation and remarkable effects. This article introduces the classification and development status of tooth whitening technologies in oral medical cosmetology, clarifies the research background of the cold light whitening technology and its importance in meeting patients' aesthetic needs. On this basis, it analyzes the traditional tooth whitening methods and their disadvantages, the new technologies of cold light whitening, and the advantages of cold light whitening compared with traditional whitening methods. Then, it focuses on the indications and contraindications of cold light whitening and provides a standardized operation process. By analyzing existing clinical data, it evaluates its whitening effect, durability, and possible side effects. By comprehensively analyzing cold light whitening, this article aims to provide valuable references for clinical practice. Future research needs to focus on the cross-innovation of materials science, photodynamics and digital technology to promote this technology to a more precise and safer stage.