To obtain the photonic crystal fiber(PCF) temperature sensor with high sensitivity,the thermal liquid mixture such as chloroform and alcohol is filled in air hole of photonic crystal fiber.The finite element method is used to analyze the influence of temperature on fiber mode area and loss.The temperature sensibivity of the loss becomes maximal by adjusting the mixing ratio,and in this way we obtain high-sensitivity PCF temperature sensor.The length of filling is 4 mm and experimental results show that the sensitivity of PCF temperature sensor is 0.75 dB/℃,which accords with theoretical simulation.The sensor is easy for demodulation,with high sensitivity and adjustable sensing interval,which has important applications in active sensing and distributed measuring.