Method for making pixel unit

The invention provides a pixel unit. The pixel unit comprises a gate electrode line, a data line, a thin film transistor, a pixel electrode, a scanning line, a signal reading line, and a PIN diode, wherein the thin film transistor is electrically connected with the gate electrode line and the data line; the pixel electrode is electrically connected with the thin film transistor; the scanning lineis arranged in parallel to the gate electrode line; the signal reading line is arranged in parallel to the data line; and one end of the PIN diode is electrically connected with the scanning line, and the other end of the PIN diode is electrically connected with the signal reading line so as to detect the light changes outside the pixel unit and output a light current according to the light changes. On the premise of not lowering an aperture ratio, the pixel unit can achieve higher detection precision by a simpler detection circuit, and the manufacturing cost is lowered.