At the beginning of creation and distribution, ancient literature was written in ancient characters. Characters are the carrier of vocabulary. Therefore, in order to have a deeper understanding of the ancient Chinese vocabulary system, it is necessary to have a basic knowledge of ancient Chinese characters. In the era of great discovery of ancient written materials, we have unique advantages in using ancient written materials to study ancient Chinese vocabulary. Some of the problems of ancient Chinese vocabulary which are difficult to solve from the perspective of past handed-down documents are expected to be explained reasonably by unearthed documents. The unearthed documents have three enlightenments for the study of ancient Chinese vocabulary. (1) Ancient documents were written in the form of ancient characters at the beginning of their creation and dissemination, among which there may be traces of the characters of the six countries in the documents of the Spring and Autumn Period and the Warring States Period. It has been proved that it is feasible to collate and interpret the difficult words in the handed down documents according to the unearthed ancient literary materials of the same time and region. The handed down version of Mu Tianzi Zhuan was unearthed in the tomb of Wei Xiangwang (so-called ″Ji Zhong″), and its characters should belong to the so-called ″Sanjin System″. In Volume 6 of this book, ″狎″ ″狃″ are mistakes of ″〖XC田.tif,JZ〗″. ″〖XC田.tif,JZ〗″ is the special structure of ″田（畋）″ in Sanjin area. (2) There are significant differences in the correspondence between the glyph and lexicon of ancient Chinese and its descendants. Some of the relationships between glyph and lexicon of ancient Chinese have not been changed by the standardization of descendants, so it has become a difficult problem for lexical interpretation to retain them in the handed down literature. The evidence of the relationship between glyph and lexicon retained in the unearthed documents provides a valuable reference for solving these vocabulary problems. The ″勳″ of ″扬文武大勳″ in the handed down version of Yizhoushu corresponds to ″剌″ in Tsinghua bamboo book Zhaigong Zhi Guming. From the evidences of literary meaning and lexicon, we can see that ″勳″ is a font error of ″剌″ 's ancient character form. (3) In the process of exegetical interpretation of ancient Chinese characters, we often encounter the situation that there are many schemes for exegetical interpretation of word meanings and parts of speech in specific fonts. The lexical evidence of unearthed documents can determine the scope of part of speech and word meanings, and help to improve the accuracy of lexical interpretation. As for the explanation of the word ″居″ in the Yanghuo chapter of Analects of Confucius， there used to be two notions of the substantive word ″kneel down″ and the non-substantive auxiliary word. The lexical evidence of ″坐，吾语女″ in Chu bamboo slips of Shanghai Museum proves that the word ″居″ here in Yanghuo chapter is undoubtedly used as the verb ″kneel down″.