The state-owned economy is the dominant force of China’s national economy and plays a strategic supporting role in achieving high-quality development. This paper takes China’s Shanghai and Shenzhen A-share state-owned listed companies from 2007 to 2021 as samples and employs the PSM-DID method to explore how non-state strategic investors affect the ambidextrous innovation output of state-owned enterprises, and the role of technological diversity in this relationship. The findings reveal that introducing non-state strategic investors promotes both types of ambidextrous innovation output in state-owned enterprises, and with a more pronounced effect on exploitative innovation output. Irrelevant technological diversity positively moderated the relationship between non-state strategic investors and exploratory innovation output of state-owned enterprises. Relevant technological diversity positively moderated the relationship between non-state strategic investors and exploitative innovation output of state-owned enterprises. Mechanism test indicates that non-state strategic investors affect the ambidextrous innovation output of state-owned enterprises through governance effect rather than resource effect. This study enriches the theoretical discussion on the relationship between mixed-ownership reform and enterprise innovation, and also provides management enlightenment for state-owned enterprises with different technological bases on how to improve the quality and quantity of innovation after implementing mixed-ownership reform.