The present disclosure provides a method for detecting cholangiocarcinoma cells. The capture rate of the cholangiocarcinoma cells of the present disclosure is higher than 70%, and a plurality of octasaccharides with high affinity and specificity can be modified on the surface of magnetic beads to capture and analyze cholangiocarcinoma cells under test, wherein the cholangiocarcinoma cells can be circulating tumor cells in cholangiocarcinoma.