Agriculutral product brands and circulation integration are important factors affecting agricultural economic growth under the new development paradigm. To form a strategic development paradigm, after clarifying the mechanism of agricultural product brands and circulation integration, this paper builds a two-way fixed effect model and a nonlinear threshold model to systematically analyze the mechanism of agricultural product brands and circulation integration and how they affect agricultural economic growth based on a comprehensively selected agricultural product geographical indication brand data and matching with city panel data. Results indicate that: agricultural product geographical indication brands show obvious spatial differences, and agricultural product brands show a convergence relationship with agricultural economic growth. Agricultural product brands and circulation integration have significant influences in promoting agricultural economic growth with obvious spatial heterogeneity. Agricultural product brands have a greater marginal effect on agricultural economic growth in the central and western regions, and the circulation integration has a greater marginal effect on agricultural economic growth in the eastern regions. From the perspective of different agricultural product brands, compared with “Geographical Indicator”, “Agricultural Product Geographical Indicator” and “Protected Geographical Indicator” have greater marginal effects on agricultural economic growth. Circulation integration has a nonlinear threshold effect on the impact of agricultural product brands on agricultural economic growth. At the national level, as the degree of circulation integration crosses a higher threshold, the marginal effect of agricultural product brands on agricultural economic growth has a nonlinear increasing trend. From the perspective of different regions, the non-linear threshold effect of circulation integration between east regions and central and western regions is heterogeneous. For the central and western regions, as the circulation integration reaches a higher threshold, the increasing marginal impact of agricultural product brands on agricultural economic growth is more obvious. Therefore, this paper suggests: to accelerate the construction of agricultural product brands and agricultural product circulation system, to pay attention to the synergy between agricultural product brand construction and circulation system construction, and to boost the process of agricultural and rural modernization with brand modernization and circulation system modernization.