Abstract: High-quality enterprising ecological environment is the important basis and core element for the construction of high-level talents highland and international science and technology innovation center. Thereby, the scientific and accurate evaluation index system is crucial to the effective evaluation and continuous optimization of enterprising ecological environment. Most existing studies directly modify the mature scales, which makes it difficult for them to accurately fit the global technological innovation situation and domestic technological talent policy dynamics. Moreover, the existing scales are more responsive to the collection needs for objective data, as well as lack of the weight design for indicators, leading to the difficulties in capturing the “weak points” of entrepreneurial ecological environment. Thereby, this study establishes a multidimensional evaluation index system for scientific and technological talents’ entrepreneurial ecological environment, drawing from the entrepreneurial ecosystem theory and new institutionalism theory. To do this, this study collected research data through semi-structured in-depth interviews and multi-source survey in three provinces and one city in the Yangtze River Delta region. On this basis, this study summarizes measure items and identifies structure dimensions of enterprising ecological environment scale based on grounded theory. Specifically speaking, this study implemented open coding, spindle coding and selective coding for original interview data, and then explored the measurement items as well as dimensions of entrepreneurial ecological environment, so as to clarify its main characteristics. The results reveal that enterprising ecological environment embraces seven constituent dimensions which are market environment, investment and financing environment, entrepreneurial culture, innovation environment, business environment, institutional environment and public service. Based on multi-source questionnaire survey, the study verifies the reliability and validity of the developed scale in the previous stage by exploratory factor analysis and confirmatory factor analysis. As a result, these seven dimensions and their forty-three items could be effectively supported by the data. Moreover, this study adopts correlation analysis and regression analysis to verify criterion validity of enterprising ecological environment by revealing the significant and positive prediction mechanisms of enterprising ecological environment for scientific and technological talents’ entrepreneurial intention and their entrepreneurial performance. Ultimately, this study developed a set of evaluation index system with seven core dimensions and forty-three items for the evaluation of enterprising ecological environment. The theoretical contributions of this study to existing literature contains following three points. Firstly, the multidimensional evaluation index system of entrepreneurial ecological environment established in this study enriches and develops the connotation structure and evaluation system of scientific and technological talents’ entrepreneurial ecological environment, providing a more comprehensive and in-depth understanding of entrepreneurial ecological environment. Secondly, this study achieved the contextualized research of scientific and technological talents’ entrepreneurial ecological environment by integrating the global technological innovation situation as well as domestic technological talent policy dynamics. Thirdly, the measurement scale developed in this study would meet the subjective evaluation needs of entrepreneurial ecological environment. Simultaneously, this study also have several policy suggestions. Firstly, this study provides evaluation index system for policy makers to evaluate the entrepreneurial ecological environment more scientifically and accurately. Secondly, this study bring “anchoring point” for policy adjustment and service improvement aimed at optimizing the construction of enterprising ecological environment.