Abstract: Based on the Huygens-Fresnel principle,the square hole Fraunhofer diffraction is simulated numerically.The theory of diffraction is verified,the diffraction patterns of non-axis space and small square hole are also obtained.This can expand the concepts of diffraction and provide a reference for better undersatnding of diffraction.

Key words: Huygens-Fresnel principle, numerical calculation, square hole Fraunhofer diffraction, MATLAB