The utility model belongs to environment protection device field relates to a cavity formula reoxygenation tidal flow wetland, including the wetland cell body, set up the filtration packing layer in the wetland cell body, filter the packing layer with vacuole formation reoxygenation layer between the bottom of wetland cell body, the lower part on cavity reoxygenation layer is provided with to be access to the outer outlet pipe of wetland cell body. Area is little, and sewage treatment is efficient, simple structure, and it is little to consume energy in the processing procedure, and the management is convenient, is fit for popularizing on a large scale.