<p>This study aimed to evaluate the environmental and ecological consequences of three consecutive beach nourishment projects (2017–2023) in Sanya Bay, Hainan, China, with emphasis on physical beach aging and ecosystem recovery processes within the context of a tropical coastal system. This work involved the use of the Before-After-Control-Impact framework, which included surveying the beach profile, sediment sampling, and sampling macrofaunal community assemblage at nourished and control sites. This step was coupled with multivariate statistical analysis and Geographic Information Systems spatial analysis to determine the physical and socioecological frameworks over several years. Beach nourishment projects profoundly affected sediment characteristics. Macrofaunal abundance and diversity also suffered substantial losses and recovered at low rates postnourishment. Recovery trajectories varied considerably between projects, with the East Bay Section (2017) surpassing the rest and attaining 89.3% control abundance and 94.2% family richness after 36 months. Central Bay Section (2023) reached 46.1% abundance recovery after 9 months. Strong seasonal influences were noted, where ecological recovery peaked in wet seasons despite heightened physical erosion. Sediment compatibility determined recovery success, with offshore dredged material outperforming quarry sediment markedly. The complex interplay among sediment type, project design, seasonal behaviors, and their resultant impacts on nourishment effects and recovery trajectories was evaluated in detail. Moreover, ecologically driven alterations within such beach systems can be performed simultaneously without compromising tropical beach defense structures.</p>