This study takes A-share private enterprises in Shanghai and Shenzhen from 2013 to 2022 as the sample to empirically examine the impact of state-owned equity on the ambidextrous innovation performance of private enterprises and its mechanism from the perspective of innovation factors. The results show that state-owned equity significantly promotes the improvement of the ambidextrous innovation performance of private enterprises, and has a greater role in promoting the breakthrough innovation performance. The mechanism analysis shows that state-owned equity can enhance the ambidextrous innovation performance of private enterprises by alleviating financing constraints, optimizing talent structure, and promoting technical cooperation. Further analysis shows that managerial myopia weakens the promotional effect of state-owned equity on the ambidextrous innovation performance of private enterprises. Heterogeneity analysis further finds that the promotional effect of state-owned equity is more significant in private enterprises in competitive industries, with high growth potential, and with a high level of digitalization.