The invention provides a screen body and a sludge and water separation device and method, and relates to the technical field of wastewater treatment. The screen body comprises at least two layers of screen nets in a cylindrical shape, a cylinder body is formed through sheathing of the screen nets, and the outer wall of the screen net on the outermost layer is sleeved with a filter cloth. Spiral conveyors are arranged between every two adjacent screen nets and in the screen net on the innermost layer respectively, the screen body further comprises a plate body used for closing the inlet end ofthe screen body in the conveying direction of the spiral conveyors, and an inlet communicated with the screen net on the innermost layer is formed in the plate body. When the screen body is used in the sludge and water separation device, the filtration effect is improved; a driving device is connected with the screen nets so as to drive the screen nets to rotate; compared with a chemical coagulation method, no coagulant is needed in the sludge and water separation method, wastewater is separated through different screen nets, the using cost of agents is reduced, the separation effect is improved, and moreover, the sludge yield is improved. In the sludge and water separation method, standing for precipitation is not needed, the wastewater can be continuously separated, and the efficiency ishigher.