In the context of global energy shortage and environmental pollution, introducing regional integrated energy system (RIES) into the electric power system is an important method to improve the proportion of clean energy in the terminal and energy efficiency. In order to realize the low-carbon economic operation of RIES, this paper firstly built the basic structural model of RIES. Furthermore, fully considering the governance cost of the carbon dioxide emissions of RIES, this paper constructed the mathematical model of RIES’ operation strategy with the lowest daily operation cost as the objective function, and then established the Markov decision process (MDP) problem of the model and introduced improved Q learning algorithm to seek the optimal operation strategy of RIES. The simulation results shown that the proposed model can realize the multi-energy complementation of RIES and the low-carbon economic operation of RIES on the basis of satisfying the balance of supply and demand, and ultimately realize the efficient and flexible use of energy.