Abstract: In order to optimise the dynamic traffic routing, the authors applies the non-linear H_∞ control method and the simple real-tin algebraic calculation method to make the system possess of robustness under the boundary disturbance, thas avoiding the tediously long off-line or on-line calculation in existing techniques and solving the DTA (dynamic traffic assignment) / DTR(dynamic traffic routing) problems of network system-optimization and user-equilibrium. The non-linear H_∞ control method is suitable to dealing with things about DTA/DTR in the advanced traffic information management system.