The invention discloses a performance evaluation method suitable for multi-region interconnected power grid contact line power control. The performance evaluation method includes for any regional power grid interconnected through a certain extra-high voltage contact line, decomposing to be an N-region tree-shaped structure interconnected power grid model, and acquiring responsibility, for power fluctuation of any contact line, of any control region by analyzing influence, of each control region, on power fluctuation on the contact lines when power disturbance occurs at a certain place of the interconnected power grid; after control targes of all contact lines of the interconnected power grid are determined, acquiring control responsibility, of a certain control region in the interconnected power grid, on the contact lines, and calculating T1 and T2 indexes used for contact line control evaluation according to the control responsibility for evaluation. By the performance evaluation method, responsibility, which should be taken from and contribution, which should be made to, power fluctuation of the contact lines, of each control region can be effectively distinguished, and an evaluation method for reasonably evaluating control performance of each region can be formulated. The performance evaluation method has good application prospect.