Ji Yun presided over the compilation of Sikuquanshu, which played an important role in preserving and sorting out the ancient cultural heritage of China. Yu Jiaxi once fully affirmed its due academic value: "After Jia (Qing) and Tao (Guang), a large number of Confucian scholars came out, and they all made great contributions and took it as a lesson." However, because the compilation of Sikuquanshu is an official act and the guiding ideology of compilation is influenced by political purposes, the recorded books are not eclectic, but have strict selection criteria. This is clearly stated in Oracle Bone Inscriptions at the beginning of Sikuquanshu. While compiling, collating and researching ancient books, they also engaged in disgraceful activities of destroying and deleting some books that were not conducive to the Qing Dynasty. While hooking up, compiling and preserving ancient books, it is also destroying and destroying culture. In this way, not only many books with precious historical value were abandoned, but also some collected books, especially many books with heresy after Song and Yuan Dynasties, lost their original features. In this sense, it is also a cultural catastrophe. The works of Song and Ming Dynasties involved the historical facts of Liao, Jin and Yuan ethnic minorities, and all of them were banned. The works collected by those who surrendered to the Qing Dynasty were banned because of lack of honesty, and some plays and novels were not allowed to spread to future generations because of corruption. Worst of all, the officials of Siku Library arbitrarily deleted books and changed the original appearance of the documents without any labels at all. Now the reliability of some books included in Siku Quanshu has become a problem. Regarding Li Zhi's remarks in the Ming Dynasty, the Qing government not only listed his works as burning books, but also denounced Li Zhi for "being heretical and unholy" and "doing whatever it takes to be a villain". (Book Collection Summary and Four Treasures of the Study Summary, volume 50, belong to the category of non-history) If Qu Dajun and other works strongly contradict the Qing Dynasty, they will naturally be destroyed; As for the works of Ming adherents who occasionally hurt the Qing Dynasty with a few words but are awe-inspiring, I will use them with a little "consideration". (Record of Emperor Gaozong of Qing Dynasty (volume 1095)) Its political purpose is obvious. According to several banned books and related files circulating at present, about 2,400 books have been completely destroyed, more than 400 books have been destroyed, and about 80,000 books have been burned. At the same time, the Qing government also launched a "literary prison". According to the Records of Qing Wen Prison, there were 48 Wen prisons within 10 years after the opening of Sikuquanshu. I'm afraid the actual situation is more than this figure.