|Among numerous authors who compose commentaries on Zhengmeng during the Ming and Qing Dynasties, Li Guangdi was the first scholar to consider whether the Great Void (Taixu) equals the Great Ultimate (Taiji). Of the numerous commentaries on the Zhengmeng, Li's Commentary on the Zhengmeng represented the state school of the Qing dynasty. Focusing on the interpretation provided by Li, this study comprised three sections. First, according to the concept that the great void equals qi, we determined the relationship between the Void and qi in Li's Commentary on the Zhengmeng. Second, we clarified the relationship among the Great Ultimate, the Great Void, and qi in Li's commentary, demonstrating that in his interpretation, Li attempted to harmonize the Cheng-Zhu school and Zhang Zai's theory of qi. Third, in the structure of the theory of qi proposed in Li's Commentary on the Zhengmeng, the Great Ultimate was a metaphysical substance, whereas the Great Void and yin–yang belonged to the functional activities of qi. Thus, Li had to jointly adjust the relative positions of other crucial concepts. Based on the first sentence of the first chapter of the Zhengmeng,＂The Great Harmony (Taihe) is called the Way (Tao),＂ we explored how Li posited concepts such as the Great Harmony, the Way, and divine transformation in the theory of qi expounded upon in the Zhengmeng. Lastly, we emphasized the insights provided by and limitations of the Commentary on the Zhengmeng in relation to the history of philosophical interpretation of the Zhengmeng during the Ming and Qing Dynasties and according to the reflective perspective presented in the Original Meaning of the Zhengmeng by Wang Zhi, a Confucian scholar who lived during the Qing Dynasty.