In the current study, the active distribution network dispatch is optimized within the distribution network without considering the transmission network. We propose an optimized dispatching and congestion management for transmission and distribution networks. We define the generalized bid function and regulating margin of the active distribution network as the connection between the transmission and distribution networks. The system is scheduled with the goal of minimizing the generation cost. Then, the congestions of transmission networks are found through power flow calculations. The schedulable distributed generators in the active distribution network participate in the congestion management. And the sensitivities of nodal power injections to the power flows are used during the congestion management. Moreover, a modified particle swarm optimization algorithm is used to solve the optimization problem. Finally, a modified IEEE 30 bus system is employed to verify the feasibility of the coordinated dispatch and the congestion management of active distribution network and transmission network.