The synchronous control of the twin-lift containers suffers from the internal parametric perturbations, friction and external disturbances commonly existing in double-container overhead crane systems. A self-tuning based robust adaptive sliding-mode control is suggested by employing a cross-coupling strategy on the basis of the operational mode analysis for the double-container system. A self-tuning switching gain is designed to suppress the uncertain disturbances. A varying boundary layer method is developed when the uncertain disturbances are persistently occurred. The global stability of the suggested controller is proved by using the Lyapunov theory. The overhead crane experimental results show the effectiveness of the proposed approach.