The power sales company is an important component of the power trading market. It can be used not only as the primary body for purchasing power from market transactions but also as the primary body for transferring power to the market and consumers, altering the distribution network’s power flow distribution and having a significant impact on the distribution network’s power supply capacity. The fundamental goal of the power sales company is to maximize the benefits by adjusting the power load distribution in response to changes in the power consumption of users. Based on the consideration of users’ flexible power consumption, this paper studied the load combination optimization modeling method of the power sales company. The building users are taken as the research object and the flexible power consumption type is determined based on various power values. The demand response data is extracted by load characteristic index and power consumption index, and the flexible power consumption law is predicted by a standardized matrix. Furthermore, using Hansen threshold theory, the load rate is computed and the grading is changed, and three groups of load combination schemes are obtained from the simulation test. Results show that the load combination of user 03, user 05, and user 07 is optimized in scheme C and the power sales profit of the power sales company is 26.31% and 22% higher than those of scheme A and scheme B, respectively. The proposed method can reduce the power purchase cost and increase the revenue of the power company by increasing the revenue from power sales.