The invention relates to the field of water treatment in environmental engineering, in particular to a sewage treatment device. The sewage treatment device is characterized by comprising an accommodating cavity body, a total optical fiber bundle, film separation cavities, splitting optical fiber bundles, aeration disks, a lower liquid level sensor, a plant growing environmental factor sensor, an upper liquid level sensor, an air pump and ventilating pipeline, and a water outlet pump and water outlet pipeline, wherein the film separation cavities are independent accommodating cavities, and are formed in the accommodating cavity body; the splitting optical fiber bundles, the aeration disks and the plant growing environmental factor sensor are separately arranged in the film separation cavities; the lower liquid level sensor and the upper liquid level sensor are arranged in the accommodating cavity body. Through the adoption of the scheme of the sewage treatment device disclosed by the invention, defects of conventional distributed sewage treatment devices are overcome, and the provided novel sewage treatment device has the advantages that not only is effluent water high in quality, but also nitrogen and phosphorus can be utilized in a recycling manner, the operating cost is reduced, and the stabilization of recovering biomass is guaranteed.