This paper attempted to maximize the membrane recovery rate by applying the Airlift pump technology to membrane washing to reduce membrane contamination in the membrane bio-reactor. A membrane bio-reactor is a technique known as the MBR. Recently, the standards for discharging water quality of public sewage treatment facilities have been continuously strengthened, and the MBR is a combination of the Biological Nutrient Removal (BNR) method and the Microfilter membrane (MF). The MBR has several advantages such as no need for sedimentation tanks, minimization of required sites, reuse of treated water, automatic operation and integration, and stable discharge water quality, but there is a membrane fouling problem that inevitably occurs due to the characteristics of the membrane. Membrane fouling is a process caused by the adhesion and accumulation of microorganisms to the pores and surfaces of the membrane. Therefore, in this paper, the airlift pump was applied to the MBR method to clean the membrane, and the washing principle of the airlift pump was applied to wash the membrane and maximize the membrane recovery rate. In the experiment, five sheets of PVDF-based MF flat membranes were used, and high-concentration MLSS was collected in an aeration tank of a public sewage treatment facility and applied as a sample. In addition, the membrane recovery rate was calculated by measuring and analyzing the flux and TMP of the membrane, and as a result of the experiment, the membrane recovery rate was analyzed to be 90% or more on average.