Colorectal cancer (CRC) has emerged as the second most prevalent cause of cancer-related mortality globally. Early identification of precancerous lesions prone to malignant transformation is pivotal in CRC prevention. Proteins, as microscopic reflections of cellular functional states, offer insights into pathological alterations within precancerous lesions through changes in their expression and function. Our review summarizes the protein research on colorectal adenomas under different sample conditions, including traditional adenomas, serrated lesions, LST, FAP and IBD. It highlights the changes in the expression patterns of key proteins and their potential mechanisms underlying the transition from precancerous to cancerous states. Additionally, it summarizes the research on post-translational modifications of characteristic protein families and associated signaling pathways, while discussing current techniques for studying protein expression and function in colorectal cancer, such as proteomics and artificial intelligence. However, current research limitations, such as small sample sizes, limited sample types, and insufficient in-depth mechanistic analysis, hinder comprehensive understanding. Future research should expand study cohorts, diversify sample types, and leverage machine learning and multi-omics approaches to develop predictive models. By doing so, a more comprehensive understanding of protein profiles during the progression from colorectal precancerous to cancerous lesions can be obtained, facilitating early CRC diagnosis and the development of targeted therapeutic interventions.© 2025. The Author(s).