Traditional research on demand response models for electric vehicles (EVs) typically focuses on electricity price incentives. From the perspective of “electricity” alone, EVs struggle to respond effectively to actual carbon emission variations. To address this, this paper proposes a low-carbon demand response mechanism based on dynamic carbon emission factors, which comprehensively considers grid-side carbon emission levels, peak-shaving requirements, and users’ charging needs. In this mechanism, EV users utilize time-varying regional carbon emission factors as the response signals to achieve electricity scheduling optimization from a “carbon” perspective. First, a model is established to account for the uncertainty of wind and PV output, and an energy-power boundary model for EVs is developed. Next, a time- and zone-based carbon emission accounting model for EVs is constructed, and a low-carbon demand response mechanism model based on dynamic carbon emission factors is formulated according to demand-side objective functions and constraints. Finally, the mechanism is applied to coordinated EV charging/discharging strategies. Case studies demonstrate that the proposed mechanism can effectively reduce distribution network carbon emissions, lower charging costs for EV owners, and mitigate load fluctuations in the power grid.