The invention provides a power utilization system and a power utilization efficiency improving method for an iron and steel enterprise, and belongs to the field of energy utilization of the iron and steel enterprise. The power utilization system comprises a reheating steam turbine, a dual-purpose motor, an air blower and a steam circulation part, wherein the steam circulation part is used for generating steam by utilizing coal steam of iron and steel production equipment; the steam circulation part communicates with the reheating steam turbine and provides steam for the reheating steam turbine; the dual-purpose motor, the air blower and a shaft body of the reheating steam turbine are arranged in series; and the air blower is used for blowing air of the iron and steel production equipment.The steam turbine is a high-parameter one-time reheating steam turbine, so that the utilization efficiency of coal gas can be improved; the dual-purpose motor, the air blower and the reheating steam turbine are arranged in series, so that power generation and power utilization are not needed in sequence, the equipment investment is reduced, and the loss of energy due to multiple times of conversion is avoided; and the dual-purpose motor can be used as a generator and can also be used as a motor, so that the air blower can stably operate, and energy cannot be wasted due to overflow.