The utility model provides an integrated unit of inserted block belongs to sewage treatment technical field for sewage treatment's rotating biological disk. The integrated unit of inserted block includes a plurality of discs and disc fixed part, the disc is the sheet structure, and its at least areal distribution has a plurality of unsmooth ribs for for providing, the microorganism in the sewage adheres to the space, a plurality of discs are piled up and are folded together and pass through disc fixed part detachably fixes integratively, forms the integrated unit of inserted block, the integrated unit of inserted block is used for installing and forms in the pivot rotating biological disk. Provide in addition based on the rotating biological disk and the sewage treatment plant of the integrated unit of inserted block, characteristics such as have easy dismouting, the transportation of being convenient for, structural design are reasonable.