This paper selects China's renewable energy enterprises as a research sample and analyzes the impacts of equity balance and executive stock ownership on these companies' innovation efficiency from 2009 to 2018. The results show that equity balance has significant and positive impacts on innovation efficiency, while there is a significant nonlinear, inverted U-shaped relationship between the executive stock ownership and innovation efficiency. In addition, with changes in the shareholding ratio of the largest shareholder, equity balance and executive stock ownership are substitutive in terms of their impacts on innovation efficiency. Therefore, this paper proposes the following recommendations. The shareholding ratio of the largest shareholder should be controlled within a reasonable range to help force executives and outside blockholders to make decisions in the company's interests. When implementing an equity balance, companies should avoid shareholders' oversupervision of executives, which may restrict executives' enthusiasm for innovation investment. A moderate degree of freedom for management executives should be appropriate. Published under license by AIP Publishing.