The coal gangue aggregate was pretreated by slurry wrapping technology. The water absorption, crushing value and deterioration behavior under dry-wet and freeze-thaw environment of original coal gangue aggregate and different slurry wrapped coal gangue aggregates were studied. The strength and durability of slurry wrapped coal gangue concrete were tested and the correlation between aggregate performance enhancement and concrete performance improvement was analyzed. XRD and SEM were used to analyze the mineral composition, microstructure and interfacial transition zone of original coal gangue aggregate and slurry wrapped coal gangue aggregate before and after dry-wet and freeze-thaw cycle. The results show that the original coal gangue aggregate has high water absorption, low hardness and obvious deterioration in dry-wet and freeze-thaw environment, while the performance of coal gangue aggregate is improved after slurry wrapping. The strength and durability of original coal gangue concrete are poor, while the performance of coal gangue concrete is enhanced after slurry wrapping. The correlation between the performance of aggregate and concrete is good. The main reason for the deterioration of coal gangue aggregate is that clay minerals soften and destabilize under dry-wet and freeze-thaw environment after absorbing water, but the wrapping slurry can isolate water, thus strengthening the performance of aggregate. Aggregate strengthening and the improvement of the bonding degree between aggregate and mortar matrix jointly promote the performance improvement of slurry wrapped coal gangue concrete.