Horticultural practice proves that plants mainly rely on their roots to absorb water, while the evaporation of water is lost from the surface of leaves. The plants themselves do not consume a lot of water, and the evaporation of water from the leaf surface can be greatly reduced if a spray film is applied to the leaf surface to prevent evaporation. The amount of water needed by plants is less than 50 % of their total. From the 1960s, the United States and other technologically advanced countries adopted the method of spraying paraffin emulsion in the agricultural field to prevent fruit trees and shrubs from dying in winter dormancy or losing water during transplanting and shipment, and in the 1970s, a large number of patents for paraffin emulsion for agricultural use appeared. Paraffin based emulsions are mainly used for: 1, Planting of tree seedlings Before planting pine and eucalyptus seedlings in the field, they were impregnated with paraffin emulsion, which significantly improved their tolerance to the effects of transplanting or to climatic conditions of adversity. Their survival rate was significantly improved due to reduced evaporation of water from their leaf surfaces. 2, Garden nursery planting In the process of pruning or transplanting, the survival rate can be significantly improved by the treatment of paraffin emulsion. If a large number of shrubs need to be transplanted during the dry season, pre-spraying with paraffin emulsion can ensure safe transplanting. 3, Drought resistance and freshness preservation After spraying with paraffin emulsion, saplings and shrubs can withstand severe drought conditions well. After flowers are picked, they can be pre-soaked in water and then treated with paraffin emulsion, which can significantly extend the life of flowers.