《汉语大字典》兼注中古音和现代音,但两者的对应关系却被时常弄错,原因是没有注意到《广韵》一类的书里头许多字都有意义相同的多个反切。字典所附的《中古音字表》甚至把反映同一个字不同读音的反切说成是“类隔切”和“音和切”。本文分两个部分:第一部分讨论《广韵》和《集韵》不同反切之间的关系,第二部分讨论中古反切和现代音的对应关系。 “Chinese Dictionary” and the middle and old notes both modern sound, but the correspondence between the two has been often mistaken, did not notice the “Guangyun” many words in the book have multiple meanings of the same multiple. The “Middle-aged Phonetic Alphabet” attached to the dictionary even describes the anti-tangent that reflects the different pronunciations of the same word as “class-cut” and “-save and cut”. This article is divided into two parts: The first part discusses the relationship between different anti-cut of Guangyun and Jiyun, and the second part discusses the correspondence between anti-tangency and modern tone.