Based on the theory of growth and spatial integration, this paper discusses the theoretical mechanism of innovation input and spatial segmentation affecting the differentiation of innovation growth by constructing the endogenous growth model of mechanism innovation including "innovation input + space segmentation → innovation revenue/growth → innovation input" from a comprehensive perspective. The theoretical results show that high innovation cost hinders innovation growth. Lower product space segmentation degree and higher technology space overflow degree are conducive to innovation growth. The empirical study finds that the accumulation of innovation plays an important role in innovation activities, while the innovation cost has a significant inhibitory effect on innovation growth. There are obvious regional differences in innovation growth of China"s high-tech industry. At the national level, the degree of product market segmentation restricts innovation growth, and the local market size has a significant positive effect on innovation growth. At the regional level, the influence of product market segmentation degree and local market size on the innovation growth in the eastern and western regions is divided. Finally, the empirical analysis of China"s high-tech industry as an example validates the theoretical proposition and puts forward some Suggestions.