利用富里叶变温红外光谱，对多元醇及其二元体系在发生固固相变时，多元醇晶体中－ Ｏ Ｈ 伸缩振动吸收峰位置随温度变化进行了讨论。实验表明，－ Ｏ Ｈ 吸收峰位置变化，既能反映多元醇发生相变的温度区间，又与转变热相对应。波数变化越大，转变热越高。变温红外光谱中－ Ｏ Ｈ 伸缩振动吸收峰的变化揭示了多元醇固固相变的机理。 Using Fourier transform infrared spectroscopy (FTIR), the position of - OH stretching vibration peak in polyhydric alcohol crystals with temperature was discussed when solid and solid phase transition occurred in polyols and their binary systems. The experimental results show that the change of - O H absorption peak can reflect both the temperature range and the heat of transformation of the polyol. The greater the wavenumber change, the higher the heat of transformation. The change of - OH stretching vibration absorption peak in infrared spectroscopy revealed the mechanism of solid-solid phase transition of polyols.