A school of Confucian classics that attached importance to exegesis and textual research during the reign of Qianlong Jiaqing in Qing Dynasty (A.D. 1736- 1820). Originated in the ancient Ming and Qing Dynasties. When they arrived in Gan's home, scholars inherited the exegetical methods of China's classical books, and made full use of them for the collation of ancient books and the study of language and characters, forming the so-called "Pu Xue" (that is, "Sinology"). From revising classics to studying historical records and philosophers, from explaining classics to studying history, geography, astronomy, calendar, temperament and laws; It has made great contributions to the collation of ancient historical materials.