An empirical test has been made of the impact of green technology innovation on corporate competitiveness by using data from A-share listed companies in Shanghai and Shenzhen from 2010 to 2019. Research has found that firstly, green technology innovation has a significant positive impact on corporate competitiveness in that the results remain robust after using instrumental variable method, replacing the core explanatory variable and the dependent variable, and applying dynamic effects to the core explanatory variable. Secondly, the intermediary mechanism test shows that the implementation of green technology innovation helps to enhance the total factor productivity of enterprises so as to achieve a low-cost leadership and innovation, thus granting them a competitive advantage with green characteristics. Thirdly, the combination of industry and finance negatively helps to regulate the promoting effect of green technology innovation on the competitiveness of enterprises. Fourthly, green technology innovation has a greater impact on competitiveness enhancement of non-state-owned enterprises and those located in eastern regions.