China has actively carried out financial cooperation with countries along the route, utilizing the new framework of financial cooperation to inject new momentum into economic growth. This paper measures the development level of China-ASEAN financial cooperation with the help of the China-ASEAN Financial Cooperation Index from 2000 to 2022, and empirically examines the impact of China-ASEAN financial cooperation on the economic growth of ASEAN countries through the fixed effect model. The study shows that China-ASEAN financial cooperation significantly contributes to the economic growth of ASEAN countries by advancing financial development, improving the degree of financial stability, and expanding financial openness. Heterogeneity analysis found that the promoting effect of China-ASEAN financial cooperation on economic growth is more pronounced in countries with high institutional quality and high economic development level.