In order to reveal the resource utilization efficiency and sustainability characteristics of the agroforestry complex system in the loess hilly region, and promote the optimization and promotion of the agroforestry complex production model, this study uses the theory and method of emergy analysis to systematically analyze the emergy input-output structure, environmental carrying effect and sustainable development potential of four typical agroforestry complex models: Walnut-purple perilla, Walnut-maize, Chinese pepper-potato, and Chinese pepper-red bean in Huanglong County, Yan'an City, Shaanxi Province. The results indicate that all four modes are highly dependent on non renewable auxiliary energy (accounting for>60%), with fertilizers and mechanical power as the main inputs. The current production mode still relies on petrochemical energy support; The investment in renewable environmental resources accounts for over 24%, with rainwater potential energy and rainwater chemical energy being the main sources, indicating that local water resources are relatively scarce, and planting heavily relies on natural rainfall. Overall, among the four production modes, the contribution of local environmental resources is limited (ESR=0.26-0.31); The significant environmental pressure (ELR=1.78-2.35) and overall low net energy output rate (EYR=1.45-5.90) indicate that the production efficiency and ecological friendliness of the composite system in this region urgently need to be improved. However, the Chinese pepper-red bean model showed outstanding performance, with EYR (5.90), ESI (2.55), and E/ESI (0.67) significantly higher than other models and the average in Shaanxi Province. Analysis found that this advantage stems from the multiple ecological functions of red beans as leguminous plants - high solar energy conversion rate, nitrogen fixation efficiency, and resource synergy advantages. On the contrary, the Walnut-maize model has the worst energy utilization efficiency due to competition from tall crops. This study proposes strategies such as optimizing the auxiliary energy structure and promoting intercropping of leguminous plants, providing scientific basis for the optimization selection and promotion of ecological agriculture models in Huanglong County and even the loess hilly area.