Clean and low-carbon is the core task of building a new power system, and the development of an integrated energy system with multiple energy flows is the key. For the “electricity-gas-heat-cooling” integrated energy system that takes carbon trading into account, the optimized configuration strategy of the “electricity-gas-heat-cooling” inter-grated energy system that simultaneously couples five types of energy storage devices and fuel cells/electrolysis cells is studied. Considering the carbon emission characteristics of the whole life cycle of each equipment in the system, the stepped carbon trading mechanism is analyzed; the effectiveness of the joint optimization of renewable energy power generation and P2G in establishing a low-carbon system is analyzed through a multi-scenario comparison, with respect to the influence of the carbon trading mechanism on the planned output and carbon reduction of each equipment of the integrated energy system; and the three coefficients of the baseline carbon price, the length of the interval, and the growth rate of the carbon price in the stepped carbon trading mechanism are discussed. The three coefficients of benchmark carbon price, interval length and carbon price growth rate of the stepped carbon trading mechanism are discussed. The results show that by rationally setting the benchmark price of carbon trading, the carbon emission of the integrated energy system of “electricity-gas-heat-cooling” can be effectively reduced, the installed capacity of low-carbon equipment can be increased, and the power and energy enterprises can be helped to realize carbon neutrality.