Abstract： The robust H2/H∞ controller based multi-objective optimization theory was designed in this paper to suppress the wind-induced vibration on transmission tower-line system and system with dynamic characteristic uncertainties. The controlled motion equation of the transmission towerline coupling system with in-plane/outplane vibration was established by using the D’alembert principle; the uncertain parameters (mass, damping and stiffness) of the system model were introduced into perturbation matrix; the robust H2/H∞ output feedback control strategy was proposed by using linear matrix inequalities (LMI) tool box of the MATLAB; and the H2/H∞_MCO (modified clipped optimal) semiactive controller was designed by introducing the MCO control algorithm into H2/H∞ active controller. Taking the Wenhe-Qingyun large span transmission tower-line system as engineering background, the numerical computation on windinduced vibration of the engineering background under non-control, combined control of both tuned mass damper (TMD) and viscoelastic damper (VED), lead rubber damper (LRD) control, fixed increment (FI) control and H2/H∞_MCO control were conducted, respectively. The results indicate that the windinduced vibration response (including tower displacements, accelerations and tower base internal forces) reduction effect of the H2/H∞_MCO control strategy are obviously superior to those of TMD+VED, LRD and FI control strategies.