The invention discloses a rotary-tillage ridger for a tobacco field. The ridger is characterized by comprising a frame and a power transmission mechanism, wherein the front end of the frame is provided with a tilling-depth adjusting mechanism; the central part of the frame is provided with a furrow-width adjusting mechanism; the rear end of the frame is provided with a rotary-tillage ridging mechanism; the rotary-tillage ridging mechanism comprises a supporting frame, a cutter shaft, rotary-tillage blades and ridging blades; the upper end of the supporting frame is symmetrically arranged at two sides of the frame; two ends of the cutter shaft and the lower ends of two sides of the supporting frame are rotatably connected; two ends of the cutter shaft located at the inner side of the supporting frame are respectively provided with a plurality of ridging blades; the cutter shafts located at the inner side of the ridging blades are provided with a plurality of rotary blades; the ridging blades have the same L-shaped structures as the rotary blades; and the cutting edge of the ridging blades has a larger width than the cutting edge of the rotary blades. According to the invention, rotation of the ridging blades pushes soil to two sides, and ridges and furrows are formed; thus, problems like uneven broken soil and overlarge soil blocks on furrow surface in the tobacco field are solved; the furrow surface has higher level; and the soil is looser.