Bases on the theory of the geometrical optics, the formula of account of Moire-fringe spacing is deduced, the principle of Moire-fringe measuring micro replacement is discussed.

• 摘要按照光的直线传播原理，利用光栅栅线之间的遮光效应，推导出了莫尔条纹间距的计算公式，叙述了莫尔条纹测量微小位移的工作原理。