According to the theory of the New Structural Economics, following comparative advantage is the “prescription” for successful economic development. According to the “diamond system” of national competitive advantage, the development of a country’s industries needs four prerequisites for having competitive advantage, including making full use of local rich resources, having a large domestic market, forming industrial clusters in the country, and having a competitive domestic market. However, the first condition of competitive advantage is actually the comparative advantage determined by the local factor endowment. The third and fourth conditions are based on the premise that the local industry meets the comparative advantage, and the industry that meets the comparative advantage can have both domestic and international markets, so it is larger than the market scale emphasized by the second condition of the diamond theory. Therefore, the establishment of competitive advantage is inseparable from the exertion of comparative advantage. Development in accordance with comparative advantage is the basis of competitive advantage. Only by fully relying on and exerting one’s own comparative advantage can one establish one’s own competitive advantage. Therefore, this article proposes that only by giving full play to the comparative advantages of various regions and forming larger industrial clusters through regional integration can we better transform our comparative advantages into competitive advantages in domestic and international markets.