With the development of the energy internet and electricity markets, microgrid clusters aim to enhance overall coordination capability, while individual microgrids within the cluster pursue more substantial autonomous operation capability, which forces the microgrid cluster to adopt more flexible optimal scheduling strategy. To this end, this paper proposes a bi-level optimized scheduling model for microgrid clusters that considers inter-microgrid energy transactions. According to the transaction mechanism proposed in this paper, the model delegates the internal optimized scheduling to each microgrid for autonomous operation, while assigning the inter-microgrid optimized scheduling to the central controller of the microgrid cluster. The two levels interact through transaction information exchange to find solutions, balancing the requirements of individual microgrids and the overall cluster. This enhances the economic efficiency and flexibility of the microgrid cluster.