Abstract: Facing the changes unseen in a century and the challenges of the COVID-19 in the world,there can be seen that the uncertainty of the international development environment is increasing,the political bureau of the Communist Party of China(CPC)has proposed that it is necessary to accelerate the establishment of a “dual circulation” development pattern in which great domestic economic cycle plays a leading role while international economic cycle remains its extension and supplement.In order to create and form a new development pattern,it should take the population size,age structure,human capital and population spatial distribution into consideration and explore their unique advantages in high-quality economic development from the comprehensive perspective.The paper found that:The huge market utility formed by Chinas huge population could promote and bring the refinement of social division of labor to foster the economic growth;Huge population size can provide stable and sufficient effective labor supply,human capital and talent reserve for economic and social development,and it can also provide the human capital support and the market demand conditions for the technological innovation and progress;By making full use of Chinas advantages of the swing space and the characteristics of the regional development differences,it could achieve the industrial upgrading and echelon transfer,maintain the integrity and coordinated development of the industrial system and optimize the allocation of human resources and natural resources.Therefore,even in the situation of the population aging and the negative population growth,as long as giving full play to the advantages of the huge population in the total supply and demand,the domestic and foreign demand,the investment and consumption,the export and import,there will be able to promote the domestic circulation and create a new development pattern where domestic and foreign markets can boost each other,so as to ensure the high-quality economic development.

Key words: population size swing, market effect, effective labor supply, labor division of industrial transfer, economic development