Recently, according to the “To Understand the Current Economy with One More Dimension” published by Li Xunlei, Chief Economist of Zhongtai Securities, China’s urbanization is likely to show a slow growth trend in the future. In fact, many people think that there is still much room for improvement in urbanization in China because the current urbanization rate is less than 60%, and the urbanization rate in developed countries is usually above 80%, that is, China should have 20% more room to go. However, Li Xunlei believes that when discussing urbanization space in the past, one dimension was often overlooked: the age structure of the population. Because population mobility is related to the age of the population, the older the age, the worse the mobility. According to data from the National Bureau of Statistics, the number of migrants in China decreased by about 5 million in 2015 and continued to decrease in the following two years. In 2016, the number of migrant workers in cities decreased by 1.6 million for the first time. In 2017, the number of domestic passengers dropped for the first time. In other words, the process of urbanization characterized by the movement of people is almost over. The rest is the urbanization of the local township. The process of urbanization in China has been relatively fast. This is related to policy orientation. However, the average age of migrant workers at present exceeds the average age of the national labor force. In the future, the trend of peasant workers returning home and returning to their hometowns will become more apparent. The reduction in the population of megacities such as Shanghai and Beijing is similar to the decline in population in major cities such as Tokyo in early 1970-90. Japanese urbanization took 25 years (1975-2000) from 75% to 80%. As China's current population structure is similar to that of Japan in the 1990s, the level of aging has increased dramatically. Therefore, if we do not consider policy factors, China's urbanization process should slow down.