The deck motion has been one of the key factors influencing the implementation of sea fight missions of carrier-based aircrafts.To decrease the interference of the deck motion during the landing process of the UAVs,we designed a deck motion compensator based on optimal preview control,which was used to form a deck motion tracking control system with the Kalman-filtering-based deck motion predictor.The system can effectively avoid the phase delay of the traditional deck compensation system by using the deck motion prediction information and the features of preview control operation.Finally,the small nonlinear fixed-wing UAV model was used for simulation.The simulation results show that the system can effectively track the deck motion,and thus improve the success rate of UAV landing.