According to the characteristics that the quantity of electric vehicles in a small range will be small, the method of determining the quantity of EV is proposed based on the unbalance development of EV firstly, the three distribution matching methods are compared and the way of choosing the distribution matching methods are given. Then, the method of judging the EV charging or not is proposed on the basis of the state of EV charging battery. Thirdly, considering the feasibility and instantaneity, the free-orderly charging strategy is proposed in this article. At last, for the EV charge demand in a particular area, this article determines the quantity of EV and weather the EV would charge or not, and then compare the free-orderly charging load curve with the disorderly charging load curve. The result shows that the difference between peak and valley of charging curve could be reduced, the peak charging load time could be shifted, the quantity of EV could be reduced and the usage rate of charging piles could be improved.