The invention discloses a structural high-efficiency and energy-saving oil-free range hood, which includes a fan, an oil filter, a hood casing, an oil hood, an illuminating lamp and a plurality of key-switches. The casing of the fan has a round double-cell or multi-cell structure with an air inlet and an air outlet; the impellers of the fan is composed of at least a group of arc-shaped passage vanes with single closed lateral and axial magnification. The main technical targets are as follows: the efficiency is improved by more than 10%, the energy is saved by more than 10%, the noise is less than or equal to 50dB, the oil absorption efficiency is more than 95%, the oil purifying rate is more than 90%, and the service life is improved by more than 3 times. The structural oil-free range hood also has the advantages of high efficiency, energy conservation, oil-freeness, clean and environment protection, convenient cleaning, etc., so as to be widely used in range hood manufacture for household kitchens, hotels, restaurants, dining halls, etc.; the comprehensive economic and technical indexes reach the leading level at home and abroad; the effects of energy conservation and emission reduction are prominent; and the economic benefits and the social benefits are remarkable.