The adjustment of enterprises’ stacked enjoyment of preferences in the revision of the 2021 corporate income tax return is a highlight. This paper takes the cost of capital use model as the basis to study the maximization of the net value of capital obtained by adopting the same optimal capital accumulation, and the utility mechanism of the reduced tax rate preferences and the halved levy preferences are studied, respectively. Finally, with high-tech enterprises as the main object of empirical research, we studied the effect mechanism of superimposed enjoyment of enterprise income tax concessions on R&D and analyzed the calculation process of the amount of superimposed enjoyment of income tax concessions. The results show that to tax-adjusted income of 60 million yuan to calculated through the original method of filing method to enjoy 1 million yuan of preferences, while the use of superimposed enjoyment of tax breaks and preferences amounted to 1,335,200 yuan. In this paper, the calculation of tax benefits enjoyed by using stacking is more accurate to reflect policy requirements and maintain the tax interests of high-tech and other enterprises.