In order to realize the low-carbon economic operation of the integrated energy system park and improve the rate of renewable energy consumption, an optimized scheduling method of the integrated energy system considering flexible load and penalty for abandoned wind, light and water under the stepped carbon trading mechanism is proposed. Based on the calculation model of stepped carbon trading, firstly, the load curve is optimized for the user demand side by combining the characteristics of flexible load; secondly, on the energy supply side, a comprehensive wind, light and water abandonment penalty model is established; and finally, an integrated energy system model including wind, light and water storage, CHP unit, gas boiler and flexible load is constructed. By comparing the scenarios, the role played by the rational dispatch of flexible loads and the introduction of the integrated wind-scenery-water penalty model on the integrated energy system in terms of reducing carbon emissions, lowering the system cost, and improving the rate of renewable energy consumption is analyzed. The results show that the proposed model reduces the carbon emissions by 59.3% and increases the renewable energy consumption rate by 18.1%, while the total operating cost of the system remains basically unchanged. By adjusting the variable penalty coefficient according to different target requirements, the comprehensive benefits of the system can be improved in disguised form.