As a large agricultural nation, China attaches great importance to agricultural development, as sustainable, regional agricultural development affects the sustainable development of China. Taking Chengdu, Sichuan Province as an example, this paper selected indicators and data from the past 15 years from the Chengdu Statistical Yearbook and applied the dissipative structure theory to establish an evaluation system for sustainable, regional agricultural development based on five main factors including economy, society, environment, education, and population. The entropy weight method was used to empower each indicator, and the changes in Chengdu’s sustainable agricultural development in the past 15 years were calculated. It was found that Chengdu’s sustainable agricultural development has been annually increasing, among which, economic and education subsystems had the greatest support for sustainable agricultural development. From 2003 to 2017, the entropy change of the total agricultural sustainable development system in Chengdu was negative, and the total entropy of the system gradually decreased. The sustainable agricultural development system in Chengdu has been developing towards a more orderly dynamic equilibrium state.