Being promoted to mega-city is the recognition of the size and status of the city by the state, and different countries may have different standards and evaluation indicators. Generally speaking, to become a megacity, you need to meet the following main criteria:

1. Population size: Megacities usually have a very large population size. Although the specific standards vary from country to country, the number of permanent residents in cities is usually required to reach a certain level, such as several million or more.

2. Economic strength: Megacities have strong economic strength and a large economic aggregate, making important contributions to the national or regional economy. There are a large number of industries and enterprises in this city, and the per capita GDP is very high.

3. Administration: Megacities should have strong administrative ability and be able to effectively manage huge population and complex social affairs.

4. Urban functions: Megacities play an important strategic and economic role in a country or region, with important political, cultural, educational, medical and scientific functions.

5. Urban construction: Megacities usually have developed infrastructure and modern urban construction, including transportation, communication, water and electricity supply and other facilities.

It should be emphasized that different countries may have different standards for identifying megacities, so the specific standards will vary from country to country. In addition, the development and promotion of cities are also related to time, and the scale and status of cities will change with the development of economy and society.