In order to improve the robust performances of Bank-to-turn control system within the morphing phase, a Bank-to-turn autopilot design for the morphing aerial bombs based on the discrete-time sliding mode control principle was proposed. The Bank-to-turn control affine system was modeled. Meanwhile, aiming at the time-varying and coupling characteristics, input-output feedback linearization was utilized to decouple the system into three independent discrete-time subsystems. The aerodynamic coefficient deviation items caused by sampling errors of the sweepback were regarded as the external uncertain disturbances, and a discrete-time sliding mode Bank-to-turn autopilot for the morphing aerial bombs was designed. The simulation results indicate that the discrete-time control system has a good robust performance for the time-varying parametric perturbations engendered by wings morphing and can realize the decoupling control among channels. The tracking delay and errors are related to the sampling period, therefore, the actual hardware performances and command tracking accuracy should be considered in selecting sampling period.