探究“双一流”建设在城市创新上的促进成效，对于实现区域创新发展水平提升的目标非常重要。本文以2013—2019年全国直辖市及地级市为研究对象，构建双重差分法实证探究“双一流”建设对城市创新水平的影响，并此基础上，通过中介效应模型进一步分析了“双一流”建设促进城市创新的机制。研究发现，第一，“双一流”政策显著“双一流”建设高校所在城市的创新水平；第二， “双一流”政策通过促进高校的研发投入水平、提升城市人力资源水平等方式，间接促进了城市创新水平；第三， “双一流”政策对不同类型城市的创新水平产生了不同程度的政策效应。

Exploring the promotion effect of "Double First Class" construction on urban innovation is very important for achieving the goal of improving the level of regional innovation and development. This paper takes the cities directly under the central government and prefecture level cities from 2013 to 2019 as the research object, and constructs a DID model to empirically explore the impact of "double first-class" construction on the level of urban innovation. On this basis, it further analyzes the mechanism of "double first-class" construction to promote urban innovation through the mesomeric effect model. Research has found that firstly, the "Double First Class" policy significantly enhances the innovation level of the cities where universities are located; Secondly, the "Double First Class" policy indirectly promotes the level of urban innovation by promoting the R&D investment level of universities and improving the level of urban human resources; Thirdly, the "Double First Class" policy has had varying degrees of policy effects on the innovation level of different types of cities.