Abstract: Renewables have the “positive externalities” of clean and low-carbon. Meanwhile, they also have the “negative externalities” of uncertainties and fluctuations. To handle the aforementioned uncertainties and fluctuations, the current electricity spot market mainly adjusts the market clearing boundary according to the operating experiences, which cannot explicitly reflect the changes in the power balance characteristics caused by the integration of renewables. As a result, the regulation function of the electricity spot market on stimulating the flexibility of power system operation cannot be effectively performed. To solve this, the impact of uncertainties and fluctuations of renewables on multiple market clearing boundaries and cost characteristics is analyzed. The idea of characterizing the aforementioned impact in the market clearing model is explored. Then, taking the frequency-regulation mileage service as an example, the impact of renewables on the frequency-regulation mileage requirement is revealed. On the basis of these, the intra-day market clearing model considering the response mode of generators to the frequency-regulation mileage requirement is proposed, which can explicitly reflect the aforementioned impact. Simulation results demonstrate that the proposed method can improve the system frequency performance while guaranteeing the system economy performance, which validates the effectiveness of the proposed method.