Greenhouse effect results in the global warming, and huge carbon emissions make the earth overwhelmed. How to reduce carbon emissions has become an urgent problem to be addressed. When the sum of wind power output and thermal power unit minimum output is larger than the load, the power balance can only be achieved through energy storage, heat storage device or abandoned wind. It can be defined as low load operating condition. During the low load period, it is difficult to absorb wind power and high energy storage cost. Firstly, the influence of deep regulation of thermal power units on generation cost and carbon emissions is considered. In this way, a stage output model of thermal power components is formulated. Carbon trading mechanism is introduced into the dispatching model of the system, and a stepbystep carbon trading cost calculation model can be formulated. Secondly, the minimum carbon emissions and generation costs are selected as the optimization objectives. Many constraints of the system are considered comprehensively. A lowcarbon multisource coordinated dispatching model with low load scenarios based on multiobjective is formulated. Then, the improved firefly algorithm is used to achieve the optimal dispatching scheme. Finally, taking a system with 10 wind farms as an example, three different experiments show that the proposed method can effectively reduce carbon emissions and improve the operating economy of the system. The influence of wind power gridconnected permeability on system operating mode is also analyzed, it shows that lowcarbon multisource coordinated dispatch in the lowload scenario is closely related to the penetration of wind power gridconnected.