A system for intercepting, conveying and clearing floating debris is composed of conveying units, each system comprises at least one section of conveying unit, and two adjacent sections of conveying units are connected by connecting pieces in turn. Each conveying unit comprises a driving mechanism, a buoyancy box and a screw conveying member; an arc-shaped through-groove is arranged on the water face of the buoyancy box in the axial direction, and the interior of the buoyancy box is a sealing structure; the screw conveying member is axially installed in the arc-shaped through-groove along thebuoyancy box, and a support frame is arranged in the middle of the arc-shaped through-groove, and a rotating shaft of the screw conveying member penetrates through the support frame from the middle ofthe arc-shaped through-groove; and the driving mechanism is installed on the buoyancy box, and the driving mechanism drives the screw conveying member to rotate. The system has the advantages of flexible and convenient arrangement; the segmented unit splicing mode is adopted, the segmented unit splicing can be carried out according to the size of the floating debris intercepting area, so as to achieve the required length of the floating debris intercepting, conveying and clearing system; the whole system has the characteristics of intelligent perception, automatic operation, high efficiency and energy saving, simple structure, easy installation, low operation cost and convenient maintenance.