Abstract: About the nature of the voice of Zhengyincuoyao which is a Zhengyin book of Guangdong Gegion, the academia seldom discussed on this problem, and their points of view are different. In order to further determine the nature of the voice of Zhengyincuoyao, we can prove it from the following three aspects. First, starting from the internal information of this book, compare the book with other related mandarin data. Second, comprehensively combine the sound system characteristics of the book. Third, strip out the phenomenon of dialect in this book. Through above methods, we can draw a conclusion that the nature of the voice of Zhengyincuoyao has a compound qualitative voice system.