Aiming at the problems of new energy curtailment, high carbon emissions and economic benefits in the distribution network with high wind and solar penetration rate, considering the joint operation of hydrogen energy utilization, fossil energy unit fuel cleaning and carbon trading mechanism, an optimal scheduling method of active distribution network considering hydrogen energy utilization, unit co-combustion and stepped carbon trading is proposed. Firstly, the mechanism analysis and model construction of hydrogen energy utilization unit composed of electrolytic cell, hydrogen storage tank, hydrogen fuel cell, methane reactor and ammonia production device are carried out, and the scheduling strategy of active distribution network considering multi-energy flow is analyzed. Then, considering the participation of ammonia and hydrogen in the combustion of fossil energy units, a mixed combustion model of fossil energy units is constructed, and then a carbon trading cost model under the stepped carbon trading mechanism is constructed. Finally, a low-carbon economic dispatch model of active distribution network is established with the goal of minimizing the sum of operating costs such as coal consumption, gas purchase and wind power curtailment. By setting up multiple operation schemes, the effectiveness of the proposed optimal scheduling method in improving the operation economy and energy cleanliness of the distribution network is analyzed and verified.