The invention discloses grass sheet impurity-removing method and equipment, relating to a method and equipment for screening and removing impurities of straw knots, grass-blades, sand, dust and the like in burweed sheets. Materials of impurities of straw knots, grass-blades, sand, dust and the like are conveyed into impurity removing equipment by using air current along the cutting direction to ensure that the materials form a rotating material flow in the impurity removing equipment, the materials are layered by using centrifugal force, and different components of the materials are discharged from different outlets according to the density. The impurity removing equipment is provided with a cylinder body capable for forming rotational flow, wherein the top end of the cylinder body is provided with a member which is positioned in the center of the rotational flow and used for separating the impurities with smaller density, an outlet used for discharging the impurities with larger density is arranged on the wall of the cylinder body, and pure materials are discharged from the lower part of the cylinder body. The invention especially realizes the separation of the materials with geometric dimensioning approaching to that of the grass-blades, grass membranes, the grass sheets and the like from the impurities, and improves the grass sheet screening quality.