The invention provides a rotary screen capable of rotating forwards and backwards and provided with spiral screening rings, and belongs to the field of screening equipment. The defects that according to an existing rotary screen, screening efficiency is low, the screening effect is poor, and a screen net is prone to be blocked are overcome. The rotary screen is composed of a rack, a motor, four rolling wheels and a screen body, wherein the motor, the four rolling wheels and the screen body are installed on the rack, the left of the rack is higher than the right of the rack, the motor is connected with one rolling wheel, the screen body comprises two rollers, weft-direction screening strips parallel with the screen body in direction and the spiral warp-direction screening rings with screening holes in ring bodies, one roller is borne on every two rolling wheels, and the weft-direction screening strips penetrate through the screening holes in the warp-direction screening rings to form the screen. In this way, screening efficiency is improved, the screening effect is optimized, and a screen net is prevented from being blocked.