Pei Songzhi (Year 372-451)’s annotations on The History of the Three Kingdoms have greatly revised, improved and enriched the original content of The History of the Three Kingdoms written by Chen Shou. The linguistics and philology value of Pei’s annotations are remarkable, which are reflected in the following three aspects. Firstly, in terms of phonetics, there are 99 phonetic notations (for 96 Chinese characters) in The History of the Three Kingdoms, and the methods are mainly Zhiyin (including "Yinru") and Fanqie, moreover they reflect the phonetic characteristics from the Later Han Dynasty to the Eastern Jin Dynasty. Secondly, there are 98 lexical annotations in total, producing new words and new meanings, and most of them are still used by later generations. Lastly, there are 39 philology annotations. Pei Songzhi annotated the rare and incomprehensible characters in the text, and also listed many opinions for reference. Additionally, Pei Songzhi attached importance to the influence of glyphs on the meanings of Chinese characters, and focused on analyzing words and textual meanings from the perspective of philology. Pei Songzhi’s annotations are concise and clear, meticulous and rigorous, and also express his own views and opinions, with distinct personal characteristics. Pei’s annotations on The History of the Three Kingdoms have profound research value and significance in linguistics and philology, which are worthy to be carefully explored, and the results will play an important role in enriching the research content of the history of Chinese language.