The oxy-fuel combustion technology and natural gas blending with hydrogen technology have good engineering application prospects in reducing system carbon emissions and promoting the integration of new energy sources. In response to the low efficiency of post combustion capture mode in integrated energy systems containing a high proportion of renewable energy, as well as the underutilization of oxygen and reaction heat generated during the electric to gas conversion process, a comprehensive energy system is established by supplying products from different stages of the electric to gas conversion process to oxy-fuel combustion power plants and gas turbines, and jointly operating oxy-fuel combustion power plants and hydrogen doped gas equipment. Based on the introduction of a reward-penalty carbon trading mechanism, a low-carbon economic dispatch model for comprehensive energy systems is established with the goal of minimizing comprehensive costs such as carbon trading costs, gas purchase costs, and coal consumption costs. Simulation analysis of case studies shows that, the proposed model can effectively reduce operating costs and system carbon emissions. The research provides a reference for the development of integrated energy systems.