In this paper, the disciplines of big shearing digital speckle interferometry are discussed by stastic optics theory.A new method-grating big shearing digital speckle intefferometry is presented.

• 本文用统计光学理论简要阐述了大错位数字散斑干涉的原理及特点，并在此基础上首次提出利用光栅作为错位元件的光栅大错位数字散斑干涉。