本文基于作者至今研究敦煌《毛诗音》残卷反切的结果,介绍其反切结构中的“类一致原则”的统计基础,并说明应用这条结构原则对阐释一些韵母如之韵、幽韵、蒸韵等拟音问题的功用。“类”是一种类似韵图“等位”的概念,“类一致”则表示反切上字所属的“类”和被切字相一致。作者指出,作为构拟中古音系的重要资料,《切韵》反切和《毛诗音》反切都有其特有的长处,最好能使二者起到相辅相成的作用。 Based on the author’s research on the anti-tangent results of the “Mao Shi Yin” residuals in Dunhuang, this paper introduces the statistical basis of “class coherence principle ” in the anti-tangent structure and illustrates the application of this structural principle to the interpretation of some vowels such as rhyme, Charm rhyme and other functions of the pseudo-sound problem. “Class ” is a concept similar to rhyme “” “class ”, “class is consistent ” means that the word “class ” to which the word belongs is the same as the cut word. The author points out that as an important source for the construction of middle-aged phonology, the counter-cutting of the “cut rhyme” and the anti-tanning of the “Mao Shiyin” have their own unique strengths, and they are best able to complement each other.