"Yongle Dadian" is the largest and unprecedented encyclopedia in ancient China. The book has 22,937 volumes and 11,095 volumes, with a total word count of about 370 million.

In the first year of Yongle in the Ming Dynasty (1403), Zhu Di, the founder of the Ming Dynasty, told Xie Jin, a Hanlin scholar: "The ancient and modern things in the world are recorded in various books, and the chapters are so vast that it is difficult to review them. If you want to collect the things contained in each book, you can sort them out. Gather and unify them with rhymes for the purpose of research... From the time of the Book of Confucius on the classics and history, there are hundreds of books, and as for astronomy, geography, yin and yang, medicine, divination, monks and Taoism, they are compiled into one book, which is not boring."

In November of the second year, the book was completed and was called "The Complete Documentation". But Zhu Di still felt unsatisfied, so he ordered Yao Guangxiao, Xie Jin and others to open a library in Wenyuan Pavilion, summoned Chinese and foreign officials and old scholars from all over the world to serve as editors, ordered the Imperial College and students from other counties and counties to copy the manuscript, and asked Guanglu Temple to provide it. Wine and food. The number of participants at that time was said to be around 3,000.

In the winter of the sixth year of Yongle, the book was completed and named "Yongle Dadian". Before this book, many similar books had been compiled in the history of our country. However, the largest volume is only more than 1,000 volumes. During the Three Kingdoms and Six Dynasties, Wei Yingxi and others compiled 680 volumes of "Huanglan", Liang had 120 volumes of "Leiyuan" by Liu Xiaobiao, Northern Qi had 360 volumes of "Xiuwendian Yulan" by Zu Ding and others; in the Tang Dynasty, there were 360 ??volumes of "Wensi" written by Wei Zheng and others. "Bo Yao" has 1,200 volumes, Xu Jingzong's "Yaoshan Wucai" has 500 volumes, Ouyang Xun's "Yiwen Leiju" has 100 volumes, Yu Shinan's "Beitang Shuchao" has 160 volumes, Zhang Changzong and others have 1,300 volumes of "Sanjiao Zhuying"; in the Song Dynasty, there are Li Fang's "Taiping Yulan" has 1,000 volumes, Wang Qinruo's "Cefu Yuangui" has 1,000 volumes, and Yan Shu's "Lei Yao" has 77 volumes.

As far as the existing books "Yiwen Leiju", "Beitang Shuchao", "Taiping Yulan" and "Cefu Yuangui" are concerned, they are all classified and copied groups of books. . "Yongle Dadian" was compiled according to the order of rhyme and purpose, and was copied word by word, which is also an unprecedented genre. The style of "Yongle Dadian" was originally compiled based on the style of "Yunfu Qunyu" written by Yin Shifu in the Yuan Dynasty and "Huixi Shiyun" written by Qianxi in the Song Dynasty. They compiled each word according to the order of "rhyme", but the length was very small. "Huixi Shiyun" has been lost, and only fragments of it exist; "Yunfu Qunyu" has only 20 volumes. "Yongle Dadian" expanded it more than 1,000 times.