Under the background of "dual carbon", a low-carbon economic scheduling strategy considering carbon trading mechanism and flexible load is proposed for the demand of multi-energy utilization and low carbon operation in the park. The framework of multi-energy coupling system is constructed, and the electric vehicle load is involved in system dispatching as a flexible load to increase the flexibility of the load side, while carbon trading cost is introduced to internalize this part of external environmental cost. An economic dispatching model of multi-energy coupling system in the park is constructed with the objective of minimizing the comprehensive cost, including the energy purchase cost, carbon transaction cost and surplus electricity income. The whale optimization algorithm (WOA) is adopted, and the Levy flight strategy and adaptive inertia weight are introduced to improve the global search and local optimization ability of the algorithm, so as to realize the efficient solution of the low-carbon economic scheduling model. The simulation results show that the convergence efficiency of the improved algorithm has increased by 50%. The introduction of carbon trading, flexible load and electric and thermal coupling equipment can reduce the overall carbon emissions of the park, promote the consumption of renewable energy, and improve the economy and environmental protection of the system.