Immigration refers to the migration of population. There was a large-scale organized migration during the Qin Dynasty, when Qin Shihuang moved six nobles to Xianyang. In just fifteen years, a Daqin empire was created, which was related to this large-scale immigration, but the decline of the Qin Dynasty was also related to this.

Shortly after the establishment of the Qin Dynasty, Qin Shihuang ordered the following people to do one thing, that is, "move the richest man in the world to 120,000 households in Xianyang". Is to move the nobles of the six countries to Xianyang, the capital of the Qin Dynasty. Such a huge project was completed soon, which greatly increased the population of the capital. Of course, this is also a way to strengthen the rule and turn Xianyang into a political and economic center. It can be said that it greatly promoted the overall economic development of the Qin Dynasty.

Of course, in addition to removing these "rich households", the Qin Dynasty also vigorously developed remote areas and moved civilians and sinners in central China to areas along the Great Wall. This is very important to resist the Huns, but it is precisely because of this practice that the Qin Dynasty has some hidden dangers of decline. However, this matter is basically good. After all, remote areas were seriously damaged during the period of Qin's unification of the six countries, in order to balance the population.

The decline of the Qin dynasty was also related to this immigration. After all, it moved the rich to the center and the civilians to remote areas. Although the nobles of the six countries live in Xianyang, they are always thinking about how to rebel. Once the peasants in remote areas began to rebel, the nobles of the six countries would unite and jointly attack the Qin Dynasty.