Abstract: More than 100 million tons of banana pseudostem can be produced in the world every year. A great challenge has been posed on the waste pollution of banana pseudostem. Conventional treatments (such as burying or burning) have wasted land resources or polluted the environment. New solutions are of great significance to protect the environment. The main component of banana pseudostem is cellulose, one of the most abundant natural polymers in wound dressings in recent years. Antibacterial dressings can be expected to prepare from the banana pseudostem for less waste pollution. The ideal wound dressing is characterized by its low cost, stable antibacterial properties, absorbing excess tissue fluid, and maintaining the humidity of the wound. Nanocellulose aerogel can be used as a dressing to accelerate wound healing, due to its low density, high porosity, and surface area. In this study, the banana nanocellulose was extracted from the banana pseudostem to prepare the aerogel dressing. The full utilization was realized on the natural antibacterial properties and excellent biocompatibility of banana cellulose, as well as the adsorption ability of aerogel. Banana cellulose was first fabricated by crushing, benzyl alcohol extraction, bleaching, and alkali treatment from raw banana fiber. The ultrasonication was then used to gain the banana nanocellulose. Finally, the aerogels with different banana nanocellulose concentrations were prepared by freeze-drying. The structure and composition were analyzed by the SEM (Scanning Electron Microscope), TEM (Transmission Electron Microscope), FTIR (Fourier Transformation Infrared Spectra), XRD (X-Ray Diffractometer), whereas, the TG was for the raw banana fiber, banana cellulose, and banana nanocellulose. The test was carried out to analyze the structure of the aerogel and the swelling rate, water retention rate, water vapor transmission rate, and antibacterial properties of the aerogel dressings. The results showed that the hemicellulose and lignin were removed from the raw banana fiber. The fiber diameter was reduced from 135 to 40 μm. The diameter of banana nanocellulose was distributed between 20-80 nm after the ultrasonic treatment, and the crystallinity reached 59.18%. The banana nanocellulose aerogel presented an interconnected three-dimensional network pore structure. The aerogel density increased, but the diameter of the pore decreased, and the porosity maintained above 97% overall, with the increase of banana nanocellulose concentration. Once the banana nanocellulose suspension concentration was 10 g/L, the swelling rate of the aerogel dressing was 3 080%, the water retention rate was 1 590%, and the water vapor transmission rate was 810 g/(m2•24 h), which was beneficial to absorb the tissue fluid and maintain the humidity of the wound. The antibacterial properties demonstrated that the inhibitory effects on the E. coli and S. aureus were achieved in the prepared aerogel dressing. The finding can provide a strong reference of banana pseudostem for the potential application in biomedicine.