It is an important way to promote the coordinated development of the country’s economy and achieve common prosperity by improving the duality pattern of urban and rural areas and promoting the development of rural economy. Theoretical and empirical studies show that both educational investment and service industry development narrow the income gap between urban and rural areas. At the same time, education investment has an inverted “U” shape on the income gap between urban and rural areas, and the development of the service industry has a positive “U”shape. This nonlinear relationship is mainly manifested in the existence of threshold effect. The threshold model shows that when education investment and service industry development cross the single threshold value, the extent to which the two narrow the urban-rural income gap is significantly deepened. From the perspective of the influence mechanism of the intermediary effect, the two widen the urban-rural income gap through the government management effect, and narrow the urban-rural income gap through the economic effect and human capital effect. Reasonable allocation of public resources and adjustment of industrial structure have become important measures to improve the quality of rural population and development.