The invention discloses a rapid detection kit for circulating tumor cells. The rapid detection kit comprises a cell density gradient separating medium, a porous diaphragm separator tube, a centrifuge tube with a volume of 5 mL, epidermal tumor marker antibodies and mesenchymal tumor marker antibodies. The kit employs a density gradient centrifugation method to remove background interference of most erythrocytes and leucocytes in blood and enrich circulating tumor cells in the blood; then epidermal and mesenchymal tumor marker antibodies, altogether four fluorescent tumor marker antibodies, are used for fluorescence labeling of the circulating tumor cells; and a general flow cytometer is used for detecting and counting the circulating tumor cells. The kit provided by the invention takes the epidermal-mesenchymal transformation process of the tumor cells into consideration, increases captured mesenchymal circulating tumor cells, improves the positive coincident rate of detection, and is high in accuracy, rapid, convenient, and low in cost and time consumption; and detection counting is automatically accomplished by the flow cytometer, so good repeatability is realized.