Abstract: This paper analyzes the influence mechanism and effect of industrial policy on R&D investment growth and disparity. Taking the listed companies of Shanghai and Shenzhen A-shares from 2008 to 2019 as the research object, the empirical results show that: The R&D investment intensity of enterprises supported by industrial policy is higher, and increases faster than that of unsupported enterprises. In the industries supported by the policy, the gap between enterprises' R&D investment has widened, resulting in the "Matthew effect" of R&D investment differentiation. The support bias analysis of industrial policy shows that high-tech enterprises with high R&D investment, high R&D personnel density can promote faster growth of R&D investment, and there is a selection mechanism of superior survival of the fittest in resource allocation within the same industry. Further analysis shows that government subsidies and tax incentives play a partial mediating effect between industrial policy and R&D investment. There is a certain degree of induced rather than spontaneous R&D investment growth, and the subsidy is a major factor in widening the R&D investment gap within the industry, while tax incentives promote joint R&D investment growth without exacerbating the R&D investment disparity. In addition, the growth rate of policy-supported enterprises relative to unsupported enterprises in the manufacturing sector is lower than that of non-manufacturing enterprises, and industrial policy helps to boost patent applications by improving investment in research and development. This paper provides a policy reference for the implementation and optimization of industrial policy and the promotion of R&D investment.