Abstract: Market-oriented trading is emerging as a necessary means to overcome the development bottlenecks facing distributed energy resources. However, its effective implementation relies heavily on a well-designed market mechanism. To address this challenge, an energy-flexibility trading method tailored to urban multi-microgrid systems is proposed. First, a two-layer energy and flexibility trading framework is developed. At the distribution-microgrid market, a tiered reward and penalty strategy is proposed to encourage microgrids to actively provide flexibility support. At the microgrid market, a bargaining-based peer-to-peer (P2P) energy and flexibility trading scheme is proposed to facilitate the efficient exchange of distributed resources. Furthermore, a cooperative game model based on asymmetric Nash bargaining theory is formulated to facilitate multi-microgrid collaboration, and a multidimensional contribution-based profit allocation strategy is designed. Comparative simulation studies demonstrate that the proposed energy-flexibility trading mechanism significantly enhances the economic dispatch performance of multi-microgrid systems and optimizes the allocation of flexibility resources.