What did Ying Zheng, King of Qin, do to consolidate the regime after the unification of the six countries in history?

In order to consolidate the huge empire with different cultures, the Qin dynasty carried out policies and reforms in politics, military affairs, economy and transportation. The political system has established a centralized system based on the emperor system, the three public officials system and the county system, replacing the title system of different princes and tycoons in the past. The law basically continued the law of Qin, and increased the emperor's power of life and death, with the prime minister only assisting. In terms of defense, the Great Wall was built to consolidate the north, the fortifications such as the Great Wall and the city piers of the six countries were destroyed, the weapons of the people all over the world were confiscated and cast into twelve gold men, and five trips to the east were made to stabilize various regions in Kanto. In terms of transportation, it is convenient for troops to go to various places to calm down the chaos, and it is also conducive to the transportation of materials in various regions. Economically, the Qin dynasty continued the policy of Shang Yang's political reform, emphasizing agriculture over commerce, encouraging farmers to increase grain production, and even having the opportunity to be knighted. In terms of industry and commerce, the currency (Qin Banliang) and weights and measures were unified, and salt and iron monopoly was implemented, but commerce was not completely banned. Businessmen such as Wushiluo and Widow Qing of Dansha who were engaged in animal husbandry were also encouraged.