The invention provides a chip structure of a photosensitivity hydrogel micro valve and a unicellular screening method. The chip structure comprises a cell suspension inlet, two sheath liquid inlets, acell suspension outlet I, a cell suspension outlet II and a cell recognition region. The chip structure has the beneficial effects that the inlet and the outlets of the micro-fluidic chip structure are connected with a border, the chip structure is in the shape of a trapezoid, channel width is gradually enlarged outwards, and capillary is horizontally inserted into the inlet and the outlets of the micro-fluidic chip. Besides, the chip is made from a PDMS material, and has certain elasticity. The capillary of varied diameters can be allowed, sealing property is guaranteed, binding with redundant glue is not needed, and the operation is simple. The micro-fluidic chip structure only needs one laser to control opening and closing of two micro valves, and a thinking is provided for control ofthe hydrogel micro valve high in integration degree. The micro valve is placed at the position close to a main flow path, and the chip structure is used for rapid separation of single cells, and can prevent interfusion of other cells.