Based on the definition of the concept of Apple grower, this chapter defines the income inequality of Apple planting that this research focuses on; from the perspective of psychology, anthropology and economics, it systematically defines the connotation, extension and characteristics of desire, and on this basis, it gives the definition of income desire in this book and analyzes the measurement method of income desire; Based on the theoretical analysis of the formation mechanism of income desire from the aspects of social comparison, desire to adapt, self-efficacy and control points, the theoretical analysis framework of income inequality affecting income desire is established; the theoretical analysis framework of income desire affecting income inequality is established with the productive input of farmers as the intermediary variable; on this basis, This paper analyzes the possible evolution path of income inequality under the interaction between income desire and income inequality, which lays a theoretical foundation for the empirical analysis of the fourth chapter, the fifth chapter, the sixth chapter and the qualitative analysis of the seventh chapter.