The invention discloses a method and device for achieving separation of plastic film residues and impurities. According to the method, separation and collection of the plastic film residues are achieved by integrating a screening method and a pneumatic separation method and using different physical characteristics of all components in a mixture of the plastic film residues and the impurities. The method comprises the specific steps that the plastic film residues and the impurities are poured into the upper end of an obliquely arranged vibrating screen, a pneumatic separation cavity is formed over the lower portion of the vibrating screen, under the condition that the vibrating screen and the pneumatic separation cavity work at the same time, stone and soil blocks with the high specific gravity leak from gaps between vibrating screen strips, the big impurities with the moderate specific gravity do parabolic motion in the pneumatic separation cavity and finally flow to the lower edge of the vibrating screen, the plastic film residues and the fine impurities with the lowest specific gravity can flow into a net-like plastic film residue frame along the pneumatic separation cavity, due to the wind force action, the plastic film residues adhere to the interior of the net-like plastic film residue frame while the fine impurities are blown out of the net-like plastic film residue frame, and accordingly the separation of the plastic film residues and the impurities is achieved. By means of the method and device, the mixture of the plastic film residues and the impurities can be well separated, the problem of traditional manual sorting is solved, and the method and device are a significant technical progress in plastic film residue processing and recycling engineering.