This article treats the establishment of the Henan Modern Agricultural Industrial Park as a quasi-natural experiment. Utilizing panel data from county-level administrative units in Henan Province spanning from 2013 to 2021, we construct a multitimepoint differences-in-differences model to examine the impact of agricultural industrial agglomeration on county economic growth. The study reveals that: (1)The establishment of the modern agricultural industrial park significantly propels county economic growth, a conclusion that holds true even after conducting various robustness checks. (2)Factor agglomeration, agricultural technological progress, and industry integration constitute the primary mechanisms through which agricultural industrial agglomeration drives county economic growth. Notably, the unique mechanism of agricultural technological progress and industry integration formed through the synergistic collaboration of the primary, secondary, and tertiary sectors distinguish it from the agglomeration observed in traditional manufacturing industries. (3)The economic growth effects of agricultural industrial agglomeration are subject to heterogeneous influences from natural endowments, economic structure, and the level of agricultural support. Specifically, counties with favorable agricultural foundations, robust industrial bases, and greater support for industrial parks exhibit more pronounced economic growth effects resulting from agricultural industrial agglomeration.