<p>The electricity-gas-hydrogen coupled energy system has advantages in energy efficiency and flexibility, which has garnered worldwide attention in recent years. However, there are multiple load fluctuations in the coupled system, which brings challenges to the operation and optimization of energy systems. In this paper, a low carbon-oriented optimization model for electricity-gas-hydrogen coupling systems is proposed, it considers the integration of gas turbine (GT), hydrogen fuel cell (HFC), power-to-gas equipment (P2G), and carbon capture and storage (CCS) devices. The carbon emission factor-based method is utilized to calculate the carbon emission of the system. To deal with multiple load fluctuations, this paper proposes a modified information gap decision theory (IGDT) method, in which the criteria importance through the inter-criteria correlation (CRITIC) method and entropy weight method (EWM) are combined to obtain the weight coefficient of each uncertainty. Simulation results based on the modified IEEE-39 node power system and Belgium 20-node gas system verify that the proposed model can reduce the carbon emission of the system by 22.4%, and it can effectively quantify the relationship between the uncertainty degree of load fluctuations and the total carbon emission.</p>