At the beginning of the Ming Dynasty, Mao Zhu Yuanjin abolished the prime minister in order to strengthen the imperial power. However, the political affairs are complicated, and the emperor can't handle it by himself anyway. Therefore, in the fifteenth year of Hongwu (AD 1382), following the system delayed by North Korea, he set up college students such as Gaihuatang, Wenhua Hall, Wuyingtang, Wenyuange and Dongge, and appointed lower-ranking officials. They only served as the secretary and adviser of the emperor, assisting him in handling official documents, memorials, etc. , and there is no power. Because college students all hold office in the palace, they are called "Cabinet". The rank of cabinet university students is plus five, and there are only middle-level officials.