Abstract: In this paper, a sliding-mode-based controller is designed for finite-time synchronization of Memristor Chaotic Systems (MCSs). It demonstrates that the synchronization errors of the MCSs reach the designed sliding-mode surface within a finite time and the finite-time stability is achieved on the surface, which implies that the finite-time synchronization for MCSs is achieved by employing the proposed sliding-mode-based controller. Furthermore, a new image encryption algorithm is proposed and implemented based on the results of finite-time synchronization. Finally, the numerical simulation and the corresponding statistical performance analysis are presented to verify the practicability, effectiveness and superiority of the presented sliding-mode-based controller and encryption algorithm, especially their potential applications in secure communication.