For the 4-DOF tower crane system, the lack of actuated number brings great challenges to the realization of accurate positioning and effective swing suppression, particularly with system uncertainties and disturbances. To address this, a model-free composite sliding mode (CSM) adaptive control method for 4-DOF tower crane system with multiple types of uncertainties is proposed. Specifically, the CSM surfaces are constructed by coupling the driving and non-driving variables to enhance the ability to suppress swing. Based on CSM surfaces, not only the asymptotic stability of the system equilibrium point is proved, but also the continuity of the designed control law is ensured. In addition, according to time delay estimation (TDE) technique, system uncertainties and disturbances are dealt with, and achieving model-free control. Finally, the controller is implemented on a 4-DOF tower crane experiment platform, and the effectiveness of the proposed control strategy is verified by four sets of hardware experiments.