The invention discloses a temperature sensor. The temperature sensor comprises a double-gate thin film transistor and a temperature sensing capacitor, and a sensing device, the current of which is changed along with changing of a temperature, is formed. The temperature sensing capacitor and the top gate electrode of the double-gate thin film transistor are integrated together, and the sensing device, the current of which is changed along with the changing of the temperature, is formed. The sensing device comprises an upper electrode plate, a capacitive dielectric layer, a lower electrode plate used as the top gate electrode, the top gate insulation layer of the transistor, a semiconductor layer, the bottom gate insulation layer of the transistor, and a substrate, which are, from top to bottom, sequentially arranged. A source electrode and a drain electrode are disposed in the top gate insulation layer. A bottom gate electrode is disposed in the bottom gate insulation layer. The temperature sensor has advantages of high sensitivity and simple circuit.