With the rapid development of renewable energy, the increasing volatility in energy supply presents challenges for the development of smart grids. Demand response (DR), as an important means, provides significant assistance in addressing this challenge. Additionally, as the number of electric vehicles (EVs) continues to grow, it becomes increasingly important to harness the potential of these mobile energy storage resources and explore their flexibility in DR capabilities. In this paper, considering the inherent constraints of electric vehicle (EV) charging and discharging demands, we have developed a methodology to evaluate the DR capabilities of EVs’ flexibility resources across different time periods. Additionally, it considers the impact of two different charging modes on the DR capability of EVs at each moment. Finally, by utilizing a real-world dataset of EV behaviors, we assessed their flexibility and response capabilities, offering a reliable reference for the integration of EVs into DR within the power system.