Virtual power plants（VPPs）can aggregate distributed energy resources to achieve economies of scale, but when different VPPs belong to different stakeholders, traditional centralized scheduling mechanisms may not be applicable. A master-slave game coordination strategy for multi-VPPs considering carbon trading is proposed for city-level distribution networks with multiple VPPs. Firstly, a carbon trading cost model is established, based on which a VPP optimization scheduling model incorporating the carbon trading mechanism is formulated. Secondly, a multi-VPP master-slave game model led by the VPP operation platform is constructed and solved using an improved particle swarm optimization algorithm. Finally, a simulation test system is set up to validate the effectiveness of the proposed method. Simulation results show that the proposed multi-VPP master-slave game strategy can effectively reduce operating costs, achieving coordinated optimal operation of multiple VPPs, and the introduction of carbon trading mechanism can bring additional benefits to virtual power plants and promote efficient consumption of renewable energy.