As integrated energy systems increasingly evolve, how to reduce carbon emissions from human production and life has become an important issue. To address the problem that the operators consider the dispatching of the system more from the perspective of economic benefits, which leads to high carbon emissions, a scheme for the construction of integrated energy systems and optimal dispatching considering the power to hydrogen equipment and stepped carbon trading is proposed. First, the power to hydrogen equipment is modeled, and its energy conversion relationship is analyzed. Then, the authors measure the carbon emission by carbon trading cost and introduce the principle of stepped carbon trading. Finally, a low-carbon optimization dispatching method is proposed. The comparison shows that the model considering stepped carbon trading can reduce carbon emission costs. Furthermore, it can reduce the daily operation cost of the system. Power to hydrogen equipment can promote the decrease of daily operation costs and reduce the demand for purchased energy at the peak of electricity consumption.