Taking 2014-2018 Shanghai and Shenzhen A-share listed companies as the research sample, adopting the method of multiple linear regression, taking the enterprise size and capital structure as the adjustment variables, this paper studies the moderating effect of R&D on the relationship between R&D and performance, with using the form of grouping regression and multiple cross sub samples to analyze and test, and studies the dual effects of ownership nature and industry effect. The results show that R&D investment is positively correlated with firm performance, and the impact of R&D investment on firm performance of large-scale enterprises is higher than that of small-scale enterprises. The size of the enterprise has a positive moderating effect on the relationship between R&D investment and enterprise performance, and the capital structure has a positive moderating effect on the relationship between R&D investment and enterprise performance. The order of the moderating effect according to the nature of equity and industry is: non-state-owned high-tech enterprises, state-owned high-tech enterprises, state-owned non-high-tech enterprises, non-state-owned non-high-tech enterprises.The capital structure of non-state-owned and non-high-tech enterprises has no significant moderating effect on the relationship between R&D investment and enterprise performance, and the moderating effect of private high-tech enterprises' capital structure is the most significant.Through multi-angle and all-round empirical analysis, it can provide reference for enterprise decision-makers in R&D investment, and make them find their own position and carry out R&D activities reasonably.