Abstract:     Under the realistic contradiction of surging input of innovation factors but slow growth of innovation output in China, this paper aims to improve regional innovation performance and promote high-quality economic development, in combination with the current reality of unbalanced regional development, this paper starts with the development strategy of big data to explore the theoretical mechanism and practical path of optimizing the business environment and improving regional innovation performance, so as to provide theoretical support for deepening the understanding of  optimization of the business environment, as well as providing theoretical support for constructing the path of optimizing the business environment, making up the regional "weak links" and enhancing innovation performance.
   Based on the analysis of the theoretical mechanism of business environment affecting regional innovation performance and the regulatory mechanism of big data development, this paper deduces the following two hypotheses: one is that optimizing business environment can improve regional innovation performance by reducing transaction costs, and there are regional differences in the direct and indirect effects of optimizing business environment affecting regional innovation performance; the other is big data development has a positive moderating effect on the relationship between optimizing business environment and improving regional innovation performance, but the moderating effect is different in different regions.
    In order to test the reliability of the above hypothesis, this paper constructs a dynamic panel model based on the municipal data and 722 private enterprises′ regional integration panel data from 2008 to 2017, and uses the SYS-GMM estimation method for empirical test. The results show that: first, although the optimization of business environment is conducive to improving regional innovation performance in general, but it has heterogeneity in different cities, showing the unbalanced characteristics of " non provincial capital strong, provincial capital weak ". Second, the combination of big data development and business environment optimization is the key to improve regional innovation performance, especially for provincial capital cities, but limited by the ability of technological learning, this effect is uncertain for non-provincial capitals. Third, the unbalanced regional characteristics of the optimization effect of business environment are due to the differences between cities in the intermediary role of transaction cost: in provincial capital cities, big data development can stimulate the intermediary role of transaction cost, enhance the indirect role of optimizing business environment, reverse the unbalanced regional characteristics of "non provincial capital strong, provincial capital weak", and comprehensively stimulate the innovation performance improvement effect of business environment optimization.
    According to the above conclusions, this paper proposes to improve regional innovation performance and promote high-quality economic development from the following two aspects: first, according to the characteristics and weaknesses of different cities, promote gradually the development of big data, expand the business environment optimization space of provincial capital cities, actively deal with the "digital divide" problem of non-provincial capital cities, and enhance the marginal effect of improving the business environment on regional innovation performance. Second, focus on the reform of business environment in non-provincial capital cities, improve the understanding of officials on optimizing the business environment, guide the local government to formulate property rights protection, administrative approval, innovative services and other programs according to their own reality, and then create a characteristic model to drive the optimization of business environment in similar regions finally form a harmonious relationship between government and enterprises, and promote the overall innovation vitality of the region.
    Compared with previous studies, the main progress of this paper is reflected in the following aspects: first, on the basis of previous studies on the relationship between business environment and enterprise innovation performance, we are committed to opening the "black box" of business environment affecting regional innovation performance, clarifying the transmission mechanism of "business environment--transaction cost--regional innovation performance", and deepening the recognition of "optimizing business environment". Second, based on the analysis of the regulatory mechanism and effect of big data development affects the relationship between business environment and regional innovation performance, this paper discusses the important application value of big data development in enhancing regional innovation performance, so as to provide theoretical support for tapping the application potential of big data and promoting high-quality development; Third, combined with the characteristics of China′s regional unbalanced development, this paper discusses the important role of big data development in balancing regional development, and proves that mining the development potential of big data combined with the characteristics of regional development can make up for the "short board" of regional development, enhance the marginal effect of optimizing business environment, and promote regional balanced development.

Key words: business environment, transaction cost, regional innovation performance, big data