In order to explore the applicability of microbial induced calcium carbonate precipitation (MICP) to cement calcareous sand in seawater environment and the wet-dry cycle resistance of MICP cemented bodies, the calcareous sands were cemented in seawater and freshwater environment respectively, and the wet-dry cycles were carried out in seawater environment. The element and mineral composition of the cemented bodies were analyzed based on the energy dispersive spectroscopy(EDS), X-ray diffraction(XRD). In addition, the relationships between mechanical properties, mass loss and wet-dry cycle were established through unconfined compressive strength test, weighing; and the weakening mechanism of the wet-dry cycle on samples were analyzed by scanning electron microscope (SEM). Results show that, in seawater environment, the cementation effect of MICP on calcareous sand is better than that in freshwater environment. The resistance to wet-dry cycle of calcareous sand cemented in seawater environment is larger than that cemented in freshwater environment. After 21 wet-dry cycles, the strength of cemented calcareous sand in seawater and freshwater environment decreased to 30% and 7.53% of the original samples, respectively. The wet-dry cycle reduces the particle surface roughness and intergranular cementation strength, which is manifested in the reduction of strength and stiffness of cemented calcareous sand in macro-characteristics.