Abstract: Circulating tumor cells (CTCs) are considered to be prerequisites for the distant metastasis and recurrence of cancer. The rapid technological advances in targeted therapy have resolved the issue of unavailable tumor tissues for late-stage cancer patients. CTCs, as substitutes for tumor tissues, represent a decisive tool for cancer treatment. Thus, the accurate counting and subsequent analysis of CTCs are significant in the prediction of tumor prognosis, evaluation of treatment efficacy, and design of individualized treatment. With the continuous development of CTC detection techniques, their accuracy has apparently increased. This article reviews the advances in the technology for CTC detection.