Abstract: China has embarked on a new modern journey towards common prosperity,it is still essential that the low-income groups stably increase their income.Support to the low-income groups is an important way to promote common prosperity,but the diversity of support models,the persistence of support duration and the intensity of support are a process of complex interest game,which asymmetrically affect the income of the low-income groups.The empirical study shows that the complex interest game induced by the diversity of support models leads to excessive diversity of support models.It reduces the effects scale economy,increases the rent-seeking opportunities,damages the potential income growth,and reduces the income of the low-income groups.Support duration generates adverse selection of support policies as well as moral hazard,stimulating the low-income groups to "wait for" supportand encouraging social "elite capture" to reduce the income of the low-income groups.In addition,support intensity increases the income of low-income groups with low elasticity,and its efficiency needs to be further improved.It is suggested that policies should be formulated to deal with the problems of excessive diversification of support models,inaccuracy support duration and imbalance of support investment,with emphasis on implementing support models such as government payment of new rural cooperative medical care,new rural insurance,industrial assistance,cultivated land protection subsidies and livelihood subsidies,so as effectively promote the smooth implementation of rural vitalization.

Key words: support model, support duration, low-income groups, income growth