The invention provides an ordered charging method and system of an electric vehicle. The method comprises the steps of building a peak and valley transfer ratio model of the electric vehicle based onhistoric electric vehicle charging state data in advance; defining a peak and valley electricity price difference constraint for the peak and valley transfer ratio model; obtaining user response ratios and peak and valley electricity price differences which satisfy the condition that exerted force of a distributed power supply is optimal at all moments by solving a charging load transfer equationincluding the peak and valley electricity price difference constraint; based on the optimal user response ratios and the peak and valley electricity price differences, guiding the electric vehicle toa corresponding charging station to be charged. By means of the ordered charging method and system of the electric vehicle, based on actual charging time statistic data, within a power grid security constraint range, the maximal ratio which can respond to the charging peak and valley electricity price users is sought, and distributed energy is absorbed to the greatest extent by reasonably distributing charging loads in terms of the time and territory.