Based on sensitivity of liquid crystal index on temperature, the temperature sensor of one dimensional liquid crystal defect photonic crystal was designed. The temperature sensor property was obtained and numerically calculated using the transfer matrix method. Using one dimensional liquid crystal defect photonic crystal, an experimental system was set up for temperature measurement. The results show that the defect peak wavelength moves to long wavelength, width of defect mode transmission peaks decreases with liquid crystal parallel medium surface, and the change is reverse for liquid crystal perpendicular medium surface. The temperature sensitivity of sensor not only is larger than that of common-material defect, but also is different for material and temperature, and increase rapidly with the liquid crystal phase-transformation point. The shift of the defect peak wavelength is nonlinear with temperature.