ABSTRACT The digital transformation of public service delivery is an important trend in the digital era; however, whether and how digital policy can improve public service quality (PSQ) remain unclear. Moreover, most studies on China’s big data pilot zone (BDPZ) digital policy have focused on economic and environmental aspects, with less attention given to its social impacts. This research designed a mixed methods study through DID and semi-structured interviews to analyse the relationship between the BDPZ digital policy and PSQ. This study proved that the BDPZ digital policy can significantlfy improve PSQ and that there are mediating effects through technology innovation and digital governance. Moreover, the technology innovation effect was due to the BDPZ policy making public service data more standardized, clear and traceable, and the digital governance effect was based on the linking mechanism and integrating mechanism. This study reveals the social impacts of the BDPZ policy and explains why technology innovation and digital governance are essential for improving public service quality.