Qiu Huan Plastics believes that the uses of ethylene are as follows: ethylene CH2=CH2, which is an important raw material for manufacturing plastics, synthesizing ethanol, acetaldehyde and synthetic fibers, and is a plant hormone. Because it can promote fruit ripening and is synthesized in large quantities before ripening, it is considered as a ripening hormone [1]. It can inhibit the thickening growth of stems and roots, the elongation of young leaves, the growth of buds and the formation of flower buds; On the other hand, it can promote the expansion and growth of stems and roots, the formation of adventitious roots and root hairs, the germination and upward growth of some seeds, and the aging or shedding of organs formed by the curved parts of buds. It can promote the flowering of pineapple and the growth of rice and water hyacinth stems. The threshold of concentration in almost all effective gases is 0.0-0. 1 μ l/L, and the maximum value is1-10μ l/L. Some fungi and most higher plants can produce ethylene, but it can be produced in large quantities in mature fruits. If the vegetative tissue is subjected to auxin or various stresses (contact, disease injury, drug treatment, etc. ), the output can be greatly increased. Methionine is biosynthesized in organisms, and its third and fourth carbons are converted into ethylene, but the properties of this synthetase are unknown. α-keto -4- methylthiobutyric acid produced by deamination of methionine or methyl propionaldehyde produced by further decarboxylation of methionine can effectively produce ethylene in the presence of hydrogen peroxide, sulfite and monohydric phenol, so it was once considered as the intermediate of ethylene biosynthesis, but the existence of methyl propionaldehyde in organisms has not been confirmed. In vitro, L. Mapson and waddell proved that ethylene was synthesized from methionine by the synergistic effect of transaminase, peroxidase and glucose oxidase under the action of hydrogen peroxide. However, through the experiment of isotope labeling compounds, it is considered that this reaction system does not work in vivo. Ethylene is also biosynthesized by substances other than methionine. -Polyethylene produces the largest amount of ethylene, accounting for about 45% of ethylene consumption; Followed by dichloroethane and vinyl chloride produced by ethylene; Ethylene is oxidized to ethylene oxide and ethylene glycol. In addition, ethylalkylation can produce styrene, ethylene oxidation can produce acetaldehyde, ethylene can produce alcohol, and ethylene can produce higher alcohols.