Abstract: Urban power grids undertake the dual tasks of electricity transmission and distribution, and their safe and economic operation directly affects urban stability and development. However, the traditional decoupled transmission-distribution dispatch mode can hardly achieve globally optimal operation of urban power grids. To address this issue, this paper proposes a cooperative dispatch method for urban transmission-distribution networks incorporating unified power flow controller based on a Stackelberg game. In this method, the transmission-network dispatcher acts as the leader, which uses linear programming to optimize its operational strategy and issues boundary bus voltage information to the distribution network dispatchers. Each distribution network dispatcher, as a follower, optimizes its local dispatch scheme accordingly and feeds back boundary power information to the leader. This iterative optimization process continues until the deviations in boundary voltages and powers between two consecutive iterations fall below specified thresholds. To validate the effectiveness of the proposed method, a single-snapshot case study is first conducted using the Matpower 39-bus system as the transmission network, with the 15-bus and 10-bus systems connected to Buses 12 and 26, respectively, serving as distribution networks. Subsequently, a multi-period case study is carried out based on actual operational data for a typical day in the eastern district of the Zhuhai power grid. The results demonstrate that, compared with the traditional decoupled dispatching mode, the proposed cooperative dispatch method exhibits significant advantages in reducing network losses and dispatch costs, thus verifying its engineering practicability.