Wang Zheng of the Qin Dynasty established the honorific title of "Emperor", calling himself the first emperor, and announced that his descendants would be called II and III, and even be inherited from generation to generation. Subsequently, he abolished the enfeoffment system nationwide and replaced it with the county system; Under the direct control of the emperor, a whole set of bureaucracy was established from the central government to the counties. On the basis of the original laws and decrees of Qin, it absorbed some provisions of the laws of the six countries and formulated and promulgated unified laws. The nobles before the Six Kingdoms were moved to Guanzhong and Bashu to prevent their separatist activities. It also explicitly prohibits the collection of weapons by the people, destroys the confiscated weapons, and casts 12 gold men.
Economically, the policy of emphasizing agriculture and restraining commerce was implemented to foster the development of feudal private ownership of land. In the thirty-first year of the first emperor (2 16 BC), landlords and yeomen who occupied land were ordered to declare the amount of land to the government and pay taxes. Their land ownership was recognized and protected by the government, and the national weights and measures system was unified with the weights and measures formulated by Shang Yang as the standard. Unify the national monetary system. In order to develop China's land and water transportation, the "car on the same track" was implemented, and the Chidao from Xianyang to Yanqi and Wu Chu and the straight road from Xianyang to Jiuyuan (now Baotou West, Inner Mongolia) via Yunyang were built. Wuchi Road was built in the southwest, and a canal was dug to connect Xiangjiang River and Lijiang River. In terms of cultural thought, based on the popular characters of Qin State, Biography was formulated and promulgated throughout the country. And using the theory that the five virtues of Yin and Yang in the Warring States period began at the end, Qin gained water virtue, the water color was black, and the final number was six. Therefore, it is stipulated that clothes, banners and flags are still black, and there are six kinds of symbols, crowns and riding systems. Water dominates yin, which represents punishment and killing, so the implementation of criminal law is aggravated on this basis. In the thirty-fourth year of the first emperor, he ordered the destruction of poems, books and hundreds of languages collected by the people, and banned private learning. Later, more than 400 Confucian scholars and alchemists participated in the escape of Hou Sheng, Lu Sheng and other immortals, all of whom were killed in Xianyang. After Qin Shihuang ascended the throne, he sent Meng Tian to crusade against the Huns, and linked the Great Wall in the northern part of Qin, Zhao and Yan during the Warring States Period, and built the Great Wall of Wan Li from Lintao (now Minxian County, Gansu Province) in the west to Liaodong in the east. After conquering Baiyue area, Guilin, Xiang Jun and Nanhai were established. At the end of the first emperor, the number of Qin counties increased from 36 counties at the beginning of unification to more than 40 counties, with the territory of "East to the Haichao, West to Lintao and Zhong Qiang, South to Beihu, North to the River, and Yinshan to Liaodong".
After the unification of the six countries, Qin Shihuang built the luxurious Epang Palace and the tomb of Mount Li, made five large-scale cruises and carved stones in famous mountain resorts to show off his prestige. In order to live forever, he sent alchemist Xu (that is, Xu Fu) to lead thousands of boys and girls to the East China Sea to seek immortality. It has consumed huge financial and human resources and deepened people's suffering. In thirty-seven years, Qin Shihuang returned to the plain and died of illness. So he wrote a book and ordered his eldest son Fu Su to be buried and succeeded by him. Going to the sand dunes (now northwest of Guangzong, Hebei Province), Qin Shihuang died of illness. Zhao Gao colluded with Hu Hai and Reese, the youngest sons of the first emperor, forged a testamentary edict, made Hu Hai a prince, and gave Fu Su the death penalty. Shortly after Qin Ershi Hu Hai ascended the throne, a peasant uprising led by Chen Sheng and Guangwu broke out. The Qin Dynasty perished.