反馈环结构是复杂系统发生动态变化的核心结构，反馈环结构分析是复杂系统具体管理对策确定的关键。如何对反馈环结构进行流程化分析，实现有效的反馈环开发管理是待深入研究的重要问题。针对以上问题，提出了关键变量关联反馈环四步分析法：首先，利用系统动力学新的入树建模法，构建系统的流率基本入树模型；接着，根据系统发展目标，确定研究的关键变量；然后，用枝向量行列式算法计算出系统全部反馈环，构建关键变量关联反馈环结构流图，确定关联反馈环结构流图主导反馈环；最后，依据关键变量主导反馈环分析，确定管理对策。以德邦规模养种系统发展为例，建立了刻画此复杂系统的含六棵入树的流率基本入树模型。根据系统发展的3大目标，确定养殖利润、年种植有机肥施用量、户猪粪年产沼液量3个关键变量。在构建3个关键变量关联反馈环结构流图基础上，根据德邦规模养种系统发展实践，结合德邦养殖业、沼液资源开发、户用沼气池建设的历史数据，确定3个关联反馈环结构流图的主导反馈环。最后，根据主导反馈环分析，确定了系统发展的3条管理对策。德邦规模养种系统实施管理对策的实践，验证了3条管理对策的有效性，验证了此方法在确定复杂系统管理对策中的可行性。关键变量关联反馈环四步分析法，为反馈环结构分析提供了一种规范性的方法，为复杂系统发展管理对策的制定提供一个可操作的流程。

The feedback loop structure is and the core structure of dynamic changes in complex systems,and the analysis based on the feedback loop structure is the key to the specific management countermeasures of such systems. How to analyze the feedback loop structure and realize the effective feedback loop development management is an important problem to be studied deeply. In order to solve the above problems, a four-step analysis method of key variable correlation feedback loop is proposed:Firstly, the flow rate is established into the basic tree model of the complex systems by using the new branch vector determinant algorithm of system dynamics. Secondly, on the basis of the system development goal, the key variables are determined. Thirdly, the total feedback loop of the system is calculated by using the vector Algorithm, key variables associative feedback loop structure flow diagram are constructed, and determines the associative feedback loop structure flow diagram's dominant feedback loop is determined. Finally, according to the key variables leading feedback loop analysis, the management strategy is determined. By taking the system of Debang scale breeding and cultivating for example, the basic tree model of the flow rate of six trees is established including. According to the three major goals of system development, the three key variables including:aquaculture profit, annual application amount of organic fertilizer application, household pig manure annual output of biogas slurry are determined. Based on the construction of three key variables associated with the feedback loop structure, according to the development of Debang scale breeding system, combined with historical data of Debang aquaculture industry, biogas slurry development, household biogas digesters construction, the dominant feedback loop of three associated feedback loop structures is determined. Finally, according to the analysis of the dominant feedback loop, the three management strategies of the system development are determined. During the Practice of Management Countermeasures of Debon Scale Breeding System, the effectiveness of the three management strategies is verified, and the feasibility of this method in determining the complex system management countermeasures is verified. The four-step analysis method of key variable correlation feedback loop provides a normative method for feedback loop structure analysis, and also provide an operational process for the development of complex systems development management strategies.