As an emerging tumor marker, the rarity and heterogeneity of circulating tumor cells (CTCs) increase the difficulty of detection. In recent years, CTCs enrichment technology based on biophysical, biochemical and microfluidic properties has been continuously developed, which has promoted the research and application of CTCs in malignant tumors diagnosis, clinical treatment and prognosis evaluation. Although there are still some deficiencies in the detection of CTCs, with the interdisciplinary integration, CTCs will play increasingly important roles in the diagnosis and treatment of malignant tumors.