The invention discloses a coal mill for improving coal dust uniformity and a method. The coal mill comprises a base and a rotary separator, wherein the rotary separator is arranged at the top end in the base, the lower end of the rotary separation is connected with a dust return cone, and a coal dust balancing device communicated with the rotary separator is arranged above the rotary separator; the coal dust balancing device comprise a coal dust distributor, a flow equalizing blade and a backflow cone; the interiors of the coal dust distributor, the rotary separator and the coal return cone are sheathed with coal dropping pipes externally sheathed with coal dropping pipe sleeves; the flow equalizing blade and the backflow cone are both arranged on the coal dropping pipe sleeve, and the backflow cone is located below the flow equalizing blade; the left part of the upper end of the coal dust distributor is provided with a coal dust main pipeline, and the right part of the upper end of the coal dust distributor is provided with a driving motor. The method for improving the coal dust uniformity comprises the step of uniformly mixing the coal dust by the action of the coal dust balancing device. The coal mill disclosed by the invention effectively solves the problems of obvious jet flow phenomenon and non-uniform coal dust mixing of conventional coal mills, so as to produce coal dust with excellent uniformity, and thus not only lowering the production cost, but also increasing the production benefit.