Submerged ecological bed for purifying eutrophic waterbody and application thereof

The invention discloses a submerged ecological bed for purifying eutrophic waterbody and an application thereof, belonging to the technical field of water environmental pollution treatment. The submerged ecological bed mainly comprises a submerged plant bed, a microbe bed, a buoyancy regulating device and an anchoring device. The upper layer of the submerged ecological bed is submerged plant, and the lower layer thereof is microbe; the lower layer microbe bed is disassemble for increasing the microbe amount at any time; the submerged ecological bed is provided with the buoyancy regulating device for regulating submerge depth and combines with each bed body by the anchoring device at the bottom part thereof; a fine bubble aerator is arranged at the bottom part thereof for fine bubble aerating; the submerged plant at the upper layer of the submerged ecological bed can generate oxygen gas by photosynthesis to form an aerobic-anaerobic microenvironment near roots, thus being favor of converting nitrogen in waterb