Abstract: To optimize decentralized composting strategies for livestock and poultry manure in rural areas, this study employed life cycle assessment (LCA) and life cycle costing (LCC) approaches to compare the environmental, economic, and social performances of two composting reactor models: the mixed-flow box and the silo system. The research evaluated the synergistic mechanisms between economies of scale and low-carbon technologies, as well as the alignment pathways between technological choices and regional development needs. And addressed the increasing demand for sustainable rural waste management systems that align with carbon neutrality goals, resource recycling, and rural revitalization strategies. In the environmental dimension, the mixed-flow box exhibited a significantly lower standardized total environmental impact potential (-0.106) than the silo system (-0.013), indicating a stronger overall environmental benefit. This advantage was primarily attributed to its solar-assisted design, which reduced fermentation electricity consumption by 56%, leading to notable reductions in climate change potential, fossil depletion, and ecotoxicity categories. Midpoint impact analysis across 18 key indicators confirmed that the mixed-flow box had lower contributions to human toxicity, particulate matter formation, and freshwater eutrophication. Contribution analysis further revealed that its production and use phases exerted less pressure on environmental systems compared to the silo. In terms of economic performance, the silo system demonstrated greater profitability and financial feasibility due to its scale advantages. The silo achieved a unit economic benefit of 79.01 CNY·t^-1, which was 8.4 CNY·t^-1 higher than the mixed-flow box. The mixed-flow box and silo composting systems exhibited significant differences in their energy consumption structure. The operational electricity consumption of the mixed-flow reactor was only 26.1 kW·h·t^-1, accounting for approximately 41% of that of the silo system (63.8 kW·h·t^-1). Financial indicators showed a net present value (NPV) of 1.9344 million CNY, an internal rate of return (IRR) of 13.04%, and a dynamic payback period (DPP) of 7.82 years. These values were well above the national benchmark discount rate (4.9%), affirming its investment attractiveness for medium-to-large-scale rural projects. Social performance analysis indicated that the mixed-flow box offered 2.7 times more employment opportunities per unit investment than the silo, making it more effective for poverty alleviation and inclusive development in labor-rich rural areas. However, silo-related jobs provided higher monthly wages, raising concerns over job quality in low-wage mixed-flow systems. To balance job quantity and quality, policy recommendations included linking government subsidies to poverty reduction metrics, such as hiring ratios of low-income households, and adopting employment quotas as seen in international practices like India’s “Green Job Quota” scheme. The study concluded that the mixed-flow box is more suitable for decentralized deployment in small village communities with dispersed manure generation, limited infrastructure, and greater labor availability. In contrast, the silo system is more appropriate for centralized operations in townships or cooperatives seeking greater economic returns and process standardization. To enhance system performance, the integration of solar energy and intelligent aeration technologies was recommended to reduce energy consumption and improve composting efficiency. Overall, this study provided a comprehensive evaluation of two representative composting technologies from a multi-dimensional sustainability perspective. The findings offer actionable guidance for policymakers and practitioners in designing localized manure treatment solutions that simultaneously address environmental sustainability, economic viability, and rural social development objectives.