The invention relates to a method for reducing power consumption of a mill exhauster by matching with duct resistance. The method comprises the following steps: (1) the width of an impeller is changed; and the flow of a working point of a fan is adjusted through changing the width of the impeller; (2) an outlet/inlet angle of a blade is changed; and the total pressure and the efficiency of the fan are adjusted to match with the air volume and the duct resistance after the width adjustment of the impeller; (3) the molded line of the blade is changed; and the inlet/outlet angle and the radius of the arched blade are determined through model tests; and (4) the current collector form is changed; and the arc radius of the throat part of a current collector is adjusted through building the model test. The method solves the problem of high power consumption caused by mismatching between the performance characteristic of the mill exhauster and the duct resistance in the operation, and reduces the power consumption of the exhauster through reducing the airflow short circuit in the inlet of the impeller and the resistance and the frictional force among the blades.