Malignant tumors represent a significant worldwide health challenge, with elevated morbidity and mortality rates necessitating enhanced early identification and individualized treatment. Liposomes, as biomimetic lipid-based nanovesicles, have developed as a multifaceted platform for detecting and treating malignant tumors due to their excellent biocompatibility, stability, and membrane fusion properties. Circulating tumor markers, such as circulating tumor cells (CTCs), extracellular vesicles (EVs), circulating tumor proteins (CTPs), and circulating tumor nucleic acids (ctNAs), play a key role in early cancer diagnosis, disease progression monitoring, and personalized therapy. Liposome-based platforms enable effective molecular recognition, targeted detection, and signal amplification by targeting circulating tumor biomarkers, significantly increasing the potential for early tumor diagnosis and treatment. This review systematically summarizes advancements in the study of liposomes concerning circulating tumor markers, including applications in targeted recognition, early detection, and disease diagnosis, while discussing present problems and prospective applications of existing technology.