Carbon emissions trading is an important means to achieve the target of low carbon and energy saving, the construction and promotion of which has been widely concerned in recent years. As carbon emitters, electricity industry is shouldering more pressure to reduce emissions and will definitely participate in carbon emissions trading. Energy saving dispatching is one of the most important ways to realize energy saving and emission reduction for electricity power companies. One kind of multi-objective optimization linear programming model for generating units under carbon emissions trading is constructed in this paper. The model is verified by a practical case analysis, which ensures the optimal allocation of power resources with multi-objective of Energy saving, emission reduction and economy, and sustainable development of electricity power companies.