Since the load ratio deflection range of existing electric energy monthly transaction schedules is small, the optimization space of integrative cost is limited and the electricity fairness constraint of impartial and open dispatching is not satisfied. For this status, this paper proposed a Gini coefficient constraint method. The method comprehensively considered the benefits of power plants, power grids and society, taking the integrative cost of monthly electricity generation as objective function. Based on the conventional constraints of the generation unit monthly load electricity, generating capacity and load ratio range, the Gini coefficient constraint between generation unit electricity deflections was introduced to ensure the electricity implementation fairness. A monthly trade schedule model under the restriction of impartial and open dispatching was built to meet the requirements of energy-saving generation dispatching. At the prerequisite of guaranteeing constraints such as generation unit electricity fairness, energy-saving and environmental protection, the scheduling results of the calculation example achieve the goal of the lowest integrative cost and win great social benefits, showing that this method is rational and effective.