Abstract: A detection system and method for the migrating cell is provided. The system is configured to detect a migrating cell combined with an immunomagnetic bead. The system includes a platform, a microchannel, a magnetic field source, a coherent light source and an optical sensing module. The microchannel is configured to allow the migrating cell to flow in it along a flow direction. The magnetic field source is configured to provide magnetic force to the migrating cell combined with the immunomagnetic bead. The magnetic force includes at least one magnetic force component and the magnetic force component is opposite to the flow direction of the microchannel. The coherent light source is configured to provide the microchannel with the coherent light. The optical sensing module is configured to receive the interference light caused by the coherent light being reflected by the sample inside the microchannel.