Objectively speaking, without neighboring cities, it is difficult to increase the population from a primary point of view. The main problem is insufficient demand. Residential, commercial and industrial development is difficult to form a virtuous circle. The distribution of low-class citizens to high-class citizens is pyramid structure. In other words, there must be many low-class citizens to maintain some high-class citizens. Most low-class citizens consume low-density and medium-density houses and engage in low-density and medium-density businesses, all industries (excluding high technology). Only when the lower class citizens and these related industries are fully developed can high-rise buildings be born and the population grow by leaps and bounds. But if you don't use plug-ins to simulate cities, an industrial lot and a low-density and medium-density business will provide too few jobs, which means that you have to spread these areas on a large scale, and the map is likely to be full before it is completed. Generally speaking, Simcity 4 does not need plug-ins, and cities with a population of more than 300,000 need 7-8 cities in the big map to be easily built. Because their needs are shared, we should also pay attention to promoting industrial specialization and establishing cities with different orientations, such as industrial, high-tech, agricultural and residential cities, in order to establish mega-commercial cities in areas with developed transportation. This is the fundamental solution.

Of course, if you don't want to build another city now, you can start from the direction of adjusting the structure of citizens, improve the network of fire control, public security, medical care and education, improve the satisfaction of these four aspects, and improve the living environment of citizens. On the one hand, it will raise regional housing prices, drive away low-income people and attract high-income people. High-density commercial and office buildings will appear more easily, thus stimulating population growth.