The smart grid emphasizes interaction between grid-load-generation, and the electric vehicle (EV) is a kind of favorable load with controllable ability. These EVs could participate in frequency regulation when the grid is suffering from imbalance between supply and demand. According to the requirement of power dispatching center, these EVs could inhibit charging and postpone the electricity demand to other time. It could also transmit electrical power to grid reversely. However, individually frequency response of each independent EV would cause excessive communication flows, and create new impact to power grid. This paper based on cloud service, assembled every EV in an area into a cluster agent, and proposed a kind of distributed cooperative control strategy to harmonize their frequency response. Firstly, the power dispatching center issues the demand request to a leader node named cooperative pinning node. Then, such pinning node releases the adjustment demand to the net work consisted of EV cluster agent nodes. Through communication and calculation on each agent nodes, the goal of fair EV load shedding would reach. Case study shows that the method could organize multiple EV cluster agents effectively and the system would be regulated faster than the original system with vehicle-to-grid participating.