Promoting low-carbon and sustainable development has become an important policy objective in the context of digital transformation. Using China’s National Big Data Comprehensive Pilot Zone (NBDCPZ) policy as a quasi-natural experiment, this study employs a staggered difference-in-differences approach to examine the policy’s effects on carbon emission quantity and carbon emission quality. The results show that the NBDCPZ reduces carbon emission quantity by 12.3% and improves carbon emission quality by 2.6%. These effects are more pronounced in the central and eastern regions and in areas with stronger government support. The analysis suggests that the NBDCPZ may affect carbon outcomes through green technological innovation and energy structure adjustment.