Abstract: Under the environment of power market, it is an important research topic how to make optimization strategy to maximize electricity benefits for electricity retailers according to electricity consumption characteristics of users. Aiming at the electricity retailers considering the coordination of power generation and consumption in medium-and long-term markets, the model of load combination optimization considering the benefits of electricity purchase and sale for electricity retailers is put forward. The demand response technology is further considered to optimize the integrated load characteristics of users. The benefits of electricity purchase and sale for electricity retailers is maximized in the market environment. At the same time, aiming at the load rebound problem of the demand response, a three-stage load rebound model is adopted. And a improved rolling optimization model considering load rebound is constructed to readjust the load value of demand response for users, which improves the load characteristics of demand response for combined users with the load rebound of demand response. Finally, the proposed model and strategy are simulated and analyzed based on the load data of industrial user group in a city of China in 2017, which verifies the effectiveness of the model.