The invention belongs to the technical field of pepper planting, and particularly relates to a fertilizing method for improving the vitamin content of green peppers. The method specifically comprisesthe following steps that root application is carried out once with fermented grape skin residue liquid at the middle stage of seedlings and the later stage of the seedlings separately; and foliage spray is carried out once with a nutrient solution in the early flowering season, wherein the nutrient solution is prepared from the following raw materials: fermented mulberry juice, citric acid chelated magnesium, bamboo leaf polysaccharide, spirulina polysaccharide, puerarin, gallic acid, ferrous sulfate and water. The method has the advantages that the division, differentiation and growth of roottissues are effectively promoted, the branch growth and the strong growth of a root system are promoted, the utilization rate of soil nutrients is increased, so that the seedlings of green pepper plants are thick and strong, the growth of leaves are vigorous, decay and fall of flowers are effectively inhibited, rapid synthesis of chlorophyll of the leaves is promoted, the photosynthesis efficiency is improved, in addition, the growth and the expansion of the green peppers are effectively promoted, the contents of folic acid, vitamin A, vitamin E, vitamin B1 and other vitamins of the green peppers are remarkably improved, so that the nutritive values of the green peppers are improved.