Reintroduction serves as a highly effective method for biodiversity conservation, as it plays a crucial role in restoring populations of endangered species and mitigating the risk of extinction. Nonetheless, achieving successful reintroduction is no simple feat; it demands a comprehensive process of monitoring and evaluating the individual behavior of the species and its interplay with the habitat. Vital aspects such as activity rhythms, home range characteristics, and habitat selection offer valuable insights into the environmental requirements of reintroduced animals. Thus, the temporal rhythms of movement patterns, home range, and habitat selection of reintroduced red-crowned cranes play a crucial role in population conservation and habitat management. This study employed GPS-GSM tracking data and advanced analytical techniques, including 3S technology, dynamic Brown's Bridge model, and habitat selection index, to investigate the daily activity rhythms, home range characteristics, and habitat selection of reintroduced red-crowned cranes (Grus japonensis) in Yancheng coastal wetland. The results indicate that the daily activity rhythms of the cranes exhibit clear periodic patterns, with the highest intensity observed during the rearing period, followed by the wintering period, hatching period, and brooding period. The activity patterns during the hatching and brooding periods are characterized by a smooth intensity of daytime activity, while those during the rearing and wintering periods exhibit a bimodal pattern. The study also found that 95% home range area of the cranes varies from (111.18±22.15) to (621.28±105.77) hm², with the largest ranges during the rearing period, followed by the brooding period, hatching period, and wintering period. Meanwhile, the core home range area varies from (0.53±0.26) to (45.78±6.66) hm², with similar patterns as the 95% home range. The overlap values of the home ranges also show periodic variation, ranging from 31.08% to 46.84% for different life cycles and from 29.20% to 76.21% for different years. Finally, the results demonstrate that the habitat selection rates of the cranes also exhibit periodic variations, with different habitats being selected during different life cycle stages. During the hatching period, the medium to high cover reed habitat is preferred, while during the brooding period, the pond habitat, the medium to high cover habitat, and the habitat within 100 m from the tidal creek and the pond are selected. During the rearing period, the pond habitat, the low and medium-low cover habitat, and the habitat within 100 m from the pond are preferred, while during the wintering period, the pond habitat, the medium-high cover habitat, and the habitat within 100 m from the pond are selected. In conclusion, this study provides a valuable scientific foundation for conservation and habitat management of the reintroduced red-crowned crane population in Yancheng coastal wetland.