With the accelerated evolution of the great changes unseen in a century, the impact of the new round of scientific and technological revolution and industrial changes on the mode of production of human society has gradually come to the forefront. To respond to the wave of the times and grasp the historical opportunities, countries are trying their best to seek a new mode of productivity. With this in mind, the concept of new quality productivity is timely, and vigorously developing new quality productivity can provide an important strategic fulcrum for China to shape new advantages in development and cope with external environmental shocks. The construction of data element market, as a key content and key deployment of element market allocation reform, will bring new impetus to the casting of new quality productivity. With the help of the quasi-natural experiment of data trading platform pilot, this article selects the sample data of 277 prefecture-level cities in mainland China from 2011 to 2021, constructs the evaluation index system of new quality productivity based on the dimensions of scientific and technological productivity, green productivity, and digital productivity, and utilizes the multi-period difference-in-differences method to validate the impact of the construction of data element market on new quality productivity and the mechanism of its action. It is found that the construction of data element market significantly promotes the improvement of new quality productivity, and this conclusion still holds after a series of robustness tests such as parallel trend test and placebo test. The improvement of new quality productivity by the construction of data element market can be realized through three mechanisms, namely, improving the accumulation of human capital, promoting the upgrading of industrial structure, and increasing the degree of economic agglomeration. The impact of data element market construction is more significant for cities in the east and cities with a higher degree of marketization. The policy effect of data element market construction has significant spatial spillover characteristics, that is, the establishment of data element market in the pilot cities can promote the improvement of new quality productivity in the neighboring cities. Based on the above findings, the article puts forward policy suggestions such as accelerating the construction of data element markets, promoting human capital accumulation, accelerating economic agglomeration, promoting the upgrading of local industries to high value-added fields, and formulating a characteristic development strategy. The innovation of the article is mainly reflected as follows. The pilot policy of data trading platform is regarded as a quasi-natural experiment, and the research perspective is sunk to the level of prefecture-level cities, so as to analyze the impact of data element market construction on new quality productivity with a more detailed scale, which not only supplements the relevant research on the economic consequences of data element market construction, but also enriches the policy toolbox for nurturing new quality productivity. The intrinsic mechanism of data element market construction affecting new quality productivity is discussed from the three perspectives of human capital accumulation effect, industrial structure upgrading effect and economic agglomeration effect, and the heterogeneous impact and spatial spillover effect of data element market construction on the enhancement of new quality productivity are systematically explored, which can provide empirical evidence and policy insights for deepening data element market reform and promoting the development of new quality productivity.