The invention relates to a foliage fertilizer. The foliage fertilizer is characterized in that the foliage fertilizer comprises the following compositions in weight percent: 20 to 30 percent of potassium citrate, 1 to 2 percent of ferrous sulfate, 1 to 5 percent of manganese sulfate, 1 to 2 percent of bluestone, 1 to 5 percent of ammonium molybdate, 1 to 5 percent of surfactant, 1 to 5 percent of complexing agent and the balance being water. The potassium citrate, micro-fertilizer and the surfactant are compounded to form the foliage fertilizer which has nutritive substances essential to the growth of plants. The compounded foliage fertilizer has strong wetting capacity, is sprayed on the leaf surface of the plant and is absorbed by the plant through corneum, or unkeratinized guard cells or pores of the leaf surface, thereby improving the utilization rate of the fertilize effect and the supplementation of the micro-fertilizer; and the fertilization method has low cost and rapid effect, and is simple and convenient.