As the world's largest manufacturing country, the rapid growth of China's manufacturing industry has historically relied on factor input. To achieve high-quality development of the manufacturing industry, China must accelerate the transformation from extensive factor input to innovation. The purpose of this study is to further explore the impact mechanisms of technological development policy on the high-quality development of the manufacturing industry. It selected data from 30 provinces and cities in China spanning from 2011 to 2021 for the study. Initially, it established a benchmark regression model to verify the positive impact of technological development policies on the high-quality development of the manufacturing industry. Subsequently, a mediation effect model was used to analyze the role of high-tech industry development in mediating this impact, and a moderation effect model was applied to study the moderating effect of the level of infrastructure informatization. Additionally, taking the industrial structure as a threshold variable, a panel threshold effect model was employed to explore the impact of technological development policy on the high-quality development of the manufacturing industry. It was found that enhancing the level of high-tech industries further facilitates the high-quality development of the manufacturing industry through technological development policy. The level of infrastructure informatization positively moderates the impact of technological development policy on the high-quality development of the manufacturing industry. Moreover, the industrial structure exhibits a threshold effect in this impact.