Abstract: A robust optimal preview servo terrain-following controller for a certain missile is designed based on polyhedron uncertainty. On condition that the object value were known and based on the guideline of LQ/H_∞, The parameters of robust controller including the state-feedback,integration segment and preview segment gains could be obtained by solving the linear matrix inequality （LMI）. Simulation results show good terrain-following performance for this robust optimal preview servo controller. Moreover,the designed controller gives a better robust performance than a general optimal preview servo controller.