A new congestion management model based on highlow settlement is proposed for the electricity market. The model combines the transaction mechanism and congestion management to eliminate congestion in branches with the minimum equivalent increase in the system regulating fee. The equality constrains are the branch overloads, the generator sensitivities, and the corresponding adjustments, respectively. By introducing the Lagrange multiplier and a relaxation factor, the nonlinear programming problem with constraints can be translated into an unconstrained nonlinear programming problem. The regulating values of the generators thus can be obtained. The proposed algorithm is verified by a 6bus system.