Abstract: A microfluidic chip comprises: a first unit which has a channel for a cell sample to pass through and is configured to separate circulating tumor cells in the cell sample; a second unit, a front end of which communicates with a tail end of the first unit, and the second unit is configured to capture single cells from the separated circulating tumor cells and subject the captured single cells to closed lysis; and a gel layer which is provided at the second unit. The microfluidic chip is configured to implement the binding of a protein molecule of the single cell with an antibody in the gel layer after the single cell is lysed. A cell separation and western blotting method using the microfluidic chip comprises: lysing circulating tumor cells, capturing, and implementing the binding of a lysate with an antibody.