The ongoing advancements in energy technology are progressively unveiling the high energy utilization benefits of comprehensive energy systems (CIES) in parks. Based on the concept of an energy hub, a CIES model including distributed power supply, gas turbine, and flexible loads is constructed by combining the characteristics of flexible loads in the park that can be leveled, shifted, and curtailed. In light of the demand response mechanism, a method for the low-carbon economic optimization operation of CIES has been developed, focusing on minimizing the total cost. This method utilizes the CPLEX solver to process the algorithm. The approach involves a comparative analysis of load distribution before and after engaging in demand response activities. Such analysis is crucial in understanding the influence of the demand fluctuations mechanism and in determining the most efficient method for adjusting flexible loads. This adjustment aims to further reduce the system costs of CIES. The findings indicate that, under the demand response mechanism, the involvement of flexible loads in CIES operations can significantly enhance the system’s economic efficiency.