To explore the capacity and value of carbon emission reduction from pumped storage, this study develops a quantitative assessment model to evaluate the carbon emission reduction effect of pumped storage based on sequential production simulation method. The model calculates the change in carbon emission reduction resulting from an increase in pumped storage capacity within a regional power system. All calculations are conducted under boundary conditions considering the planned installed capacity of the N provincial power system in China between 2030 and 2060. The findings reveal that increasing pumped storage capacity by 1200 MW leads to a carbon emission reduction ranging from 1.6 to 1.8 million tons for the entire power system in scenarios spanning from 2030 to 2060. Additionally, the analysis of overall carbon emission re-duction trends across different years indicates that each additional increment of 1200MW pumped storage results in a reduction between 0.8–1.8 million tons of carbon emissions. As the carbon price gradually rises, the benefits derived from reduced emissions can reach up to 13 billion yuan by adding 6000MW of pumped storage in 2060. The carbon reduction benefits of pumped storage are thus substantial. Overall, pumped storage plays a positive role in facilitating the transition of power systems towards low-carbon and zero-carbon emissions.