Abstract: The agglomeration of the civil aviation industry is an important factor in achieving optimal regional resource allocation and regional economic development with high-end supply and demand markets, deep industrial collaboration, and great transportation convenience. Provincial data from 2009 to 2020 are used to explore the effects of three agglomeration patterns in the civil aviation industry — specialized agglomeration, diversified agglomeration, and competition effect — on regional high-quality economic development, and further test the effects of agglomeration at different stages. The results show that as the level of agglomeration rises, both specialized agglomeration and diversified agglomeration of the civil aviation industry have an inhibitory effect on regional high-quality economic development before becoming a driver of that, and competition effect is positively related to regional high-quality economic development.