The present invention relates to the field of medicine production, and specifically refers to a preparation method of loquat cough syrup, which specifically includes the following steps: (1) drying and pulverizing raw materials such as loquat leaves, poppy shells, basilica, baipei, morus alba, and platycodon grandiflorum, Mix, add water and refrigerate; (2) take out the product after refrigerating, add a surfactant, ultrasonically obtain the extract, filter, heat and concentrate the filtrate and store it at room temperature for later use; (3) take sucrose and add water, After heating and mixing evenly, add citric acid and sodium benzoate to obtain a sucrose mixed solution; (4) dissolve menthol and essence in ethanol to obtain an ethanol solution; (5) mix the extract, sucrose mixed solution and ethanol solution, Stir, stand still, filter, add water to the full amount, and mix well to obtain the target product. The invention achieves antibacterial and solubilizing effects by increasing the concentration of flavonoids and controlling the concentration of surfactants, and optimizes the quality and curative effect of the syrup; in addition, flavonoids are the original substances in the syrup, and rhamnolipids are also used in the food and drug industry , neither will have any adverse effect on the syrup.