The entry of technology enterprises serves as the innovation engine for achieving high-quality economic development. Utilizing a dataset that matches the registration information of industrial and commercial enterprises with 283 prefecture-level cities from 2004 to 2018，this paper adopted the establishment of the Yangtze River Delta Urban Economic Coordination Committee as a quasi-natural experiment，and used the machine learning method to identify the impact of unified market construction on the entry of technology enterprises. The results showed that the construction of a unified market significantly stimulates the increase in the number of technology enterprises and the enhancement of their scale，and the above promotion effect is particularly pronounced in samples characterized by smaller city size，higher financial constraints and weaker government innovation support. The mechanism analysis revealed that the construction of a unified market facilitates the entry of technology enterprises through the effects of talent agglomeration，technology agglomeration，and venture capital agglomeration. Further research uncovered that，in comparison with core cities，the construction of a unified market has a stronger effect on the number and scale of technology enterprises entering peripheral cities，thereby contributing to regional balanced development. The above findings have not only provided a novel perspective for understanding the economic effects of unified national market construction，but also provided insights for the in-depth promotion of unified national market construction and the formulation of policies aimed at regional balanced development.