Ventilation Method for Vegetable Plastic Film Greenhouse and Vent

A ventilation method for a vegetable plastic film greenhouse and a vent are provided. The ventilation method comprises making side vents at the two sides of a greenhouse, wherein the side vents are made as follows: determining the positions of the side vents on the films at the two sides, applying a cover film on an upper side of the side vents by an electric heating apparatus, then putting a transparent wide adhesive tape respectively on a top end and a bottom end of a pre-opened side vent, making an opening, by a blade, on the film from the top end of the side vent downwards to the bottom end thereof to form a plurality of strips, and alternately bundling the strips spaced apart from each other by a bundling rope to form a cross type side vent; and the front vent and the upper vent are made in basically the same manner. For a ventilation purpose, the cover film on each vent is rolled up and fixed with a tension rope to expose the vent. When ventilation is not needed or it rains, the cover film is put down, and then the edge of the cover film is closely attached to the greenhouse film, so as to achieve the purpose of sealing and heat preservation. FIGURES OF THE SPECIFICATION Step 1 m 2Z345 7 'I Step2