A comprehensive evaluation method of power quality based on incentive and punishment mechanism is proposed.By analyzing the dynamic nature of all indices according to their quality，the good quality part is awarded while the poor quality part is punished.The power quality of regional power grid containing multiple indices is evaluated from three-dimensional of index，time-series and area.Firstly，the continuity and the discreteness of the indices are analyzed，and the linear state transformation is applied to simulate the dynamic development trends of each index.Secondly，the incentive and punishment mechanism model of each index is established.Thirdly，the per-unit processing index evaluation values in each period are calculated by the integral manner according to the incentive and punishment control line.Then，the evaluation values of all indices in every time period are obtained by thevertical and horizontal”scatter degree method.Finally，the evaluation values of the power quality in the whole time series are summated with the minimum variance theory，and the influence of power quality in different periods to the final evaluation results is reflected by adjusting the time factor.The realistic example demonstrates that this method can easily differentiate the quality of different evaluation objects.