From the “two cities” linkage of Guangzhou-Shenzhen to the “three cities” linkage of Guangzhou-Dongguan-Shenzhen “three-city”，it is an inevitable trend from the “jumping” cooperation of two relatively separated regions to the integrated development of three closely connected urban complexes. In the context of the construction of “two districts”，the linkage of “two cities” and the integrated trend of “three cities” in Guangzhou，Dongguan and Shenzhen，the development strategy of Guangzhou-Dongguan integration and the discussion on the impact of the linkage between Guangzhou and Shenzhen on the integration of Guangzhou and Shenzhen，the high-quality development of the two cities and the construction of the Greater Bay Area are of great and far-reaching significance.