Diagnosis of nutrition is a method of assessing the intake and loss of nutrients based on the results of a chemical analysis of nutrients present in fruit trees and soil. The nutritional status of fruit trees significantly affects the growth and development of fruit trees, in order to ensure healthy growth and fertility of fruit trees, the correct nutritional status must be ensured. Nutrition can accurately and in a timely manner understand the state of nutrition of the fruit tree on the basis of diagnostic analytical data, provide the basis for accurate and timely appropriate measures according to the results of the diagnosis and rationalize and validate fertilization. The diagnosis of nutrition has therefore become an important step for agricultural production and agricultural scientific and technological research in the world.