Abstract: Coal gangue (CG), the most abundant industrial solid waste in China, poses significant ecological and environmental risks to surrounding mining regions. Given that incorporating coal gangue into concrete is among the most efficient disposal methods, this paper provides a comprehensive review of its composition, the effects of its usage on concrete properties, and the specific conditions for using coal gangue as coarse aggregate, fine aggregate, and mineral admixture. The review emphasizes how variables such as dosage, particle size, and water-cement ratio influence the workability of fresh concrete, as well as the mechanical properties and durability- including water absorption, frost resistance, chloride ion penetration resistance, carbonation, and sulfate attack resistance-of hardened concrete. Key findings highlight significant regional variations in the composition and performance of coal gangue. When used as an aggregate, it is crucial to minimize its carbon and sulfur content, crushing value, and water absorption while optimizing dosage, particle size, and water-cement ratio. For its use as a mineral admixture, considerations include reducing particle size (to below 0.074 mm and activating the coal gangue powder.) The recommended maximum dosages for coal gangue as coarse aggregate, fine aggregate, and mineral admixture are 45%, 20%, and 10%, respectively. The paper also details performance enhancement techniques for coal gangue aggregates and mineral admixtures, such as thermal activation, surface coating with cement mortar, water glass treatment, and microbial mineralization. Thermal and mechanical activation are highlighted as key methods for boosting the reactivity of mineral admixtures. This study elucidates the mechanisms behind improving coal gangue's performance as aggregate and admixture and identifies research gaps and challenges, offering insights for advancing coal gangue utilization and the development of sustainable building materials.