Excessive manganese content in groundwater, when used as a drinking water source, can lead to severe adverse effects on human productivity and daily life. This study designed an integrated purification system that integrates aeration with a fluidized bed containing birnessite and a gravity-driven ceramic membrane process. The system was operated for a total of 58 days to efficiently purify manganese-contaminated groundwater. Initially, a predetermined birnessite suspension was pre-aerated for 28 days without water production in the membrane pool, followed by the initiation of gravity-driven water production through the ceramic membrane. By the 38th day of the system's fluctuating operation, the concentration of manganese ions in the effluent was reduced to below 0.1 mg/L, which complied with the Chinese Health Standards for Drinking Water Quality (GB 5749－2022). Additionally, the membrane flux was finally stabilized at 9～10 L/(m²·h). Aeration effectively employs the lateral shear force generated by the bubbles to retard the deposition of birnessite on the membrane surface during operation, thereby maintaining the fluidized suspension state of birnessite in the membrane pool. Concurrently, the analysis of microbial-related indicators, along with Raman, XRD, particle size, SEM-EDS, and other characterization results, suggests that after manganese ions in the water were adsorbed by the birnessite particles, under the action of microbial oxidation and chemical oxidation by birnessite, a manganese-active filter membrane with self-catalytic oxidation properties was formed, realizing a virtuous cycle of highly efficient removal of manganese ions from groundwater.