With the continuous improvement of people's living standards, cut flowers are increasingly welcomed by people. However, cut flowers are prone to spoilage and have a short viewing life. Therefore, understanding the causes of cut flowers and extending their viewing time can reduce the loss of flowers after harvest in quantity and quality. This article reviews the physiological and biochemical causes of changes in cut flower quality for reference by producers of cut flowers. First, the causes of cut flowers aging 1. The type of cut flower differs from the variety of cut flowers in its variety. Such as: Anthurium flower bottle life up to 20 days -40 days, Strelitzia refrigerated shelf life at room temperature conditions up to 14 days -30 days, while Gerbera bottle plug life is only 3 days - 8 days. The vase life of cut flowers of the same type of different varieties is also very different. According to statistics, vase cut flowers of different varieties such as anthurium, carnation, rose and lily are twice as long. For example, the species of Poolster in Anthurium flowers has a vase life of 30 days, while the NovaAurora breed only has 15 days. 2. In order to maintain its freshness and quality, water cut flowers must maintain a high moisture content and swell, otherwise cut flowers will fade and die. The water content of cut flowers usually reaches 70%-80%. After the fresh cut flower was isolated, the water balance between the transpiration of the leaf surface and the water absorption of the root was destroyed, resulting in a greater amount of transpiration than water absorption, resulting in water deficit. For example, one of the main reasons for the "branch neck" of the Chinese rose is that the stem tissue loses water and the degree of swelling of the cell decreases, and the young stem is bent under the effect of the gravity of the bud. Paull et al. believe that the main reason for the senescence of cut flowers is the lack of water within the petal tissue due to the clogging of flower stems, which accelerates the decline of cut flowers. In addition, the environmental humidity also affects the cut flower lifespan. For example, the cut carnation cut flower life is 2 to 3 times longer at near-saturated humidity than at 80% humidity. 3. Carbohydrates Carbohydrates (especially glucose) are important substances in cut flowers. It is a kind of respiratory matrix and provides energy for the life activities of cut flowers. Its content is directly related to the quality of cut flowers. Tests have shown that the sugar content of gladiolus cut flower is directly related to its ornamental and plug-in resistance; the higher the starch content in the petals during harvest, the longer its vase life. 4. Ethylene ethylene has a close relationship with cut flower senescence. Cut flowers produce ethylene during the aging process, and ethylene has the effect of promoting aging, which eventually leads to the decline of the cut flowers. Cut flowers with faster ageing produce faster ethylene. In addition, respiration, mineral content, organic acids, protein content, and the rate of degradation of chlorophyll, protective enzymes, etc., are all related to the ageing of cut flowers. Second, cut flowers to keep fresh measures 1. Choosing the appropriate type and variety of cut flowers as growers first consider the post-harvest life of various cut flowers. If the cultivated land is close to the market, the demand of consumers for cutting flowers in various seasons is relatively constant, and there are many varieties and types of cut flowers that can be selected; if the cultivated land is far from the market, only cut flowers with long life and suitable for long-term storage and transportation can be selected. Species and breeds. 2. Strengthen the cultivation and management level of cut flowers before harvesting During the cut flower production process, the level of cultivation management directly affects the quality and post-harvest changes of cut flowers. First of all, the management of fertilizer and water is an important guarantee for the normal growth and development of cut flower and the formation of cut flower quality. Improper fertilization can affect the quality of cut flowers. For example: Excess nitrogen fertilizer will reduce the quality of cut flowers and shorten the vase life of cut flowers. The application of nitrate nitrogen fertilizer in chrysanthemum growth stage is more conducive to the improvement of cut flower quality than ammonia nitrogen fertilizer. During the cultivation period, keeping the soil relatively dry is beneficial to the development of its root system, and it can increase the content of CTK and other hormones in cut flowers, which is beneficial to the post-harvest quality maintenance. At the same time, we must strictly grasp the environmental conditions at the time of cultivation to create appropriate temperature, humidity, and light for the growth of cut flowers. This is the basis for improving the quality of cut flowers and extending the life span of vases. 3. Timely Control of Pests and Diseases Strict control of pests and diseases during cut flower cultivation is essential for improving quality and prolonging the life of cut flowers in vases. Such as: Dahlia, lily, chrysanthemum, Zinnia, Chinese rose, etc. susceptible to pests and diseases, so that plant growth is blocked, leaves, flowers discoloration or deformity, reduce the cut flower quality and ornamental value. 4. The most appropriate cutting stage for harvesting fresh cut flowers at appropriate developmental stages differs depending on the type, variety, season, and environmental conditions of the flowers. In general, the more cuts are taken at the later stages of flower development, the shorter the vase life of cut flowers is. Therefore, in the premise of guaranteeing the normal opening of buds without affecting the quality, they should be cut as far as possible during the bud stage. Such as: Aster, Strelitzia, chrysanthemum, carnation, rose, Gladiolus, etc. should be cut in the bud stage. Some spikes cut flowers (such as aconite, non-tobacco, etc.), must be cut at the base of the inflorescence of 1 - 2 flowers, otherwise the buds will not be able to open normally. There is also a class of flowers that must be harvested when the flowers are fully open, such as: orchids, dahlias, daisies and pods. 5. Application of preservatives to cut flowers In order to improve the quality of cut flowers and extend the life of the vases, preservatives are often used to treat cut flowers. Currently used preservatives generally contain carbohydrates, bactericides, ethylene inhibitors, growth regulators, and minerals. According to the experiment, cutting Gladiolus cut flowers with preservatives can significantly increase the number of flowers, increase the number of flowers, and extend the vase life. Treating carnations, lilies and other cut flowers with preservatives containing ethylene inhibitors for 5 minutes to 24 hours can significantly inhibit their ageing.