Abstract: Effectiveness evaluation is a key tool for supervising ecological restoration. Applying evaluation findings rationally helps sustain restoration benefits, while developing a scientifically sound evaluation index system forms the essential foundation and a critical focus of this work. Ecological restoration of abandoned mines is vital for advancing the practical application of the “two mountains” theory concept and implementing the “carbon peaking and carbon neutrality” strategy. To evaluate this restoration scientifically, this study establishes an evaluation index system based on the objectives and characteristics of abandoned mine projects. Guided by the principles of prioritizing ecological benefits while balancing socio-economic gains and long-term sustainability, and adhering to criteria of indicator applicability, methodological standardization, and data accessibility, the system encompasses three dimensions: ecological benefits, socio-economic benefits, and effectiveness maintenance. It includes ten specific indicators, such as key ecosystem area, vegetation coverage, and environmental quality. The system is tests using a case study of an abandoned mine restoration project in Shenzhen City. The evaluation yields an overall score of 88.2, classifies the project as “good”. Notably, both ecological and socio-economic benefits score above 95%, indicating the project successfully achieved its core ecological goals—optimizing landscape patterns, improving environmental quality, enhancing ecosystem functions, and mitigating risks—while generating significant socio-economic returns. However, effectiveness maintenance scored poorly, revealing issues like inadequate post-restoration management and insufficient long-term monitoring. The case study confirms the high applicability of the proposed index system. Its results objectively, accurately, and reliably reflect restoration outcomes. This system provides valuable insights for evaluating other abandoned mine restoration projects and offers a practical reference for advancing ecological restoration evaluation practices nationwide.