This review summarizes the research progress of circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vesicles (EVs) in cancer liquid biopsy. CTCs, ctDNA, and EVs are emerging biomarkers with distinct advantages and strong complementarity. CTCs are derived from circulating cancer cells and can reflect tumor characteristics. ctDNA is a fragment of DNA released by tumor cells into the bloodstream and can be used for early cancer detection and monitoring. EVs contain tumor-derived materials such as DNA, RNA, proteins, lipids, and metabolites and have potential as cancer biomarkers. These three biomarkers have been used in various clinical trials, but their clinical utility is still being studied. The review discusses the latest technologies for isolating, characterizing, and detecting CTCs, ctDNA, and EVs, as well as the most recent developments in the study of potential liquid biopsy biomarkers for cancer diagnosis, therapeutic monitoring, and prognosis prediction. The potential and challenges of using CTCs, ctDNA, and EVs for precision medicine are also evaluated. The review highlights the importance of these biomarkers in cancer diagnosis, treatment monitoring, and prognosis prediction, and emphasizes the need for further research to improve their clinical application.This review summarizes the research progress of circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vesicles (EVs) in cancer liquid biopsy. CTCs, ctDNA, and EVs are emerging biomarkers with distinct advantages and strong complementarity. CTCs are derived from circulating cancer cells and can reflect tumor characteristics. ctDNA is a fragment of DNA released by tumor cells into the bloodstream and can be used for early cancer detection and monitoring. EVs contain tumor-derived materials such as DNA, RNA, proteins, lipids, and metabolites and have potential as cancer biomarkers. These three biomarkers have been used in various clinical trials, but their clinical utility is still being studied. The review discusses the latest technologies for isolating, characterizing, and detecting CTCs, ctDNA, and EVs, as well as the most recent developments in the study of potential liquid biopsy biomarkers for cancer diagnosis, therapeutic monitoring, and prognosis prediction. The potential and challenges of using CTCs, ctDNA, and EVs for precision medicine are also evaluated. The review highlights the importance of these biomarkers in cancer diagnosis, treatment monitoring, and prognosis prediction, and emphasizes the need for further research to improve their clinical application.