With the proliferation of corpora, various syntactic analysis methodologies have been developed. However, syntactic analysis of Chinese sentences demands a theory that focuses more on word order and the interaction between content and function words, which is satisfied by pattern grammar theory. This study investigates the effectiveness of pattern grammar theory in the analysis of Chinese sentence structure and explores the linguistic characteristics of official documents by establishing a description system for structural complexity in Chinese. Statistical methods such as skewness, kurtosis, and correlation analyses were employed to evaluate the system's performance. The findings confirm the effectiveness of pattern grammar in analyzing Chinese sentence structure by showing that it can accurately reflect the unique properties of Chinese official documents, such as the preference for fixed collocations, declarative sentences, and flat structures. Based on the above findings, this study provides a semantically compatible and innovative theoretical system for analyzing Chinese sentence structures.