Abstract: The diffraction characteristics of terahertz waves are analyzed and explored by using different width

of diffraction screens. According to the terahertz wave diffraction characteristics，the width variation of the

diffraction screen is divided into three stages. The optical path variation and intensity distribution of the terahertz

wave are reflected by the time delay and peak amplitude parameters of the terahertz time-domain spectrum. The experiment

can be used as an extension of the knowledge of diffraction in light in class and as an example of the combination

of diffraction theory and practice in physics teaching.

Key words: terahertz wave, straight edge diffraction, optical path, intensity