Concerning the effect of the parameter uncertainty caused by environmental temperature, we present a robust control algorithm for the fiber optical voltage transformer (FOVT) to achieve optimized dynamic performance. The principle of the FOVT based on closed-loop detection is analyzed and the system model is established. Based on the system model and the optimized dynamic performance index, the robust controller is investigated to suppress the effect of the forward gains variation. Furthermore, we give a design criterion in terms of linear matrix inequality (LMI) for the proposed control. Finally, the experimental results show that the control has strong robustness against parameter uncertainty for improving the dynamic performance of the FOVTs.