本文进一步证验了：就快速而准确测定立方晶体的线性热膨胀来说，用Ｘ射线衍射仪直接测量不同温度的衍射角比测量不同温度的点阵参数更好，用新技术测飞利浦ＰＷ＿（１５３０ＱＳ）型ＬｉＦ与广州产的高纯ＬｉＦ单晶在室温下的线性热膨胀系数分别为α＿（ＰＷ）＝（３．３７±０．０２）×１０￣（－５）／℃与α＿（ＧＺ）＝（３．３３±０．０３）×１０￣（－５）／℃ This paper further tests: For the rapid and accurate determination of the linear thermal expansion of cubic crystals, it is better to use X-ray diffractometer to directly measure the diffraction angle of different temperature than to measure the lattice parameters of different temperature. With the new technology, the PW_ (1530QS) The linear coefficients of thermal expansion of LiF and LiF single crystals produced in Guangzhou at room temperature were respectively α PW = 3.37 ± 0.02 × 10 -5 / ℃ and α GZ = 3.33 ± 0.03) × 10 ~ (-5) / ℃