The development of the agricultural economy has brought the agricultural pollution, and agricultural pollution has restrained the growth of the agricultural economy and endangered public health. Since the Economic Reform opened up, China has promulgated many policies that have benefited farmers, developed the agricultural economy, and improved agricultural material levels. However, the growth in the agricultural economy has also resulted in significant environmental pollution from pesticides, agricultural fertilizers and agricultural plastic film. Agricultural pollution can affect public health, therefore it is necessary to study the relationship between agricultural economy and agricultural pollution. In this paper, the relationship between the agricultural economy and agricultural pollution is studied by using decoupling index method, taking Chengdu, Sichuan Province, China as an example, and verified by the data of 2008–2017 years of Chengdu. It was found that the decoupling index for pesticide use and per capita gross agricultural production showed “strong decoupling” ideal states in six years. From 2009–2017, the value of it increased from 0.065743–1.597385, and its decoupling state gradually transited to stable strong decoupling. The chemical fertilizer use was found to have a “strong decoupling” ideal state in five years. The value of it decreased from 1.028854–(−0.512702), while its state gradually changed to strong decoupling. However, agricultural plastic film only has one “strong decoupling” state with its value of decoupling index changed from −0.380824–(−0.250250). The increased use of plastic film has resulted in increased agricultural pollution. The research results show that growing with the development of Chengdu’s agricultural economy, the use of pesticides and fertilizers has been decreasing. Chengdu’s agricultural economy and agricultural pollution were found to have a healthy and coordinated development. The development of agricultural economy has not caused much damage to the agricultural environment. In addition, with the decline of agricultural pollution, public health problems will also be reduced.

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.