Nan said the contents of "Shentongqi": This book mainly tells the health preserving methods of Taoism and expounds the relationship between the author and Confucianism, Buddhism and Taoism. It is China's ancient ideological works and literary classics.

The Divine Power Device, also known as the Divine Power Device of Zhouyi, was written by Wei Boyang in the Eastern Han Dynasty. His theory combines the merits of Zhouyi, Huang Lao and Dan Huo, and expounds the ways of alchemy and internal cultivation with the theory of Yin and Yang change of Zhouyi, which proves that man, heaven and earth and the universe are the same body, with the same merits and different uses.

It is not only the theoretical source of Taoist health preservation, but also the pioneering work of China's ancient chemistry, pharmacology, astronomy and calendar, such as "gunpowder", one of the four great inventions that China people are proud of, and its principle comes from this book. Because it involves many subjects, it is difficult and obscure, and it is known as the "heavenly book".