In high-speed satellite communication systems, the problem of inter-symbol interference (ISI) becomes increasingly prominent as the data transmission rate increases. To effectively mitigate this issue, this paper proposes a blind equalization algorithm that first performs timing synchronization followed by a dual-mode switching mechanism. The proposed algorithm initially employs timing synchronization to resample the received signal, ensuring accurate symbol boundary alignment. Subsequently, a dual-mode switching strategy is implemented: first, the Modified Constant Modulus Algorithm (MCMA) is applied for preliminary equalization, accelerating convergence and ensuring the correct convergence direction; then, the algorithm switches to an improved Decision-Directed (DD) equalization scheme to achieve superior steady-state performance. By integrating timing synchronization with the dual-mode switching mechanism, this approach leverages the rapid convergence property of MCMA and the high-precision equalization capability of the DD algorithm, making it particularly suitable for the complex and dynamic channel conditions encountered in satellite communications. Through comparative analyses of constellation diagrams, mean squared error (MSE), and ISI across different modulation schemes and channel conditions, simulation results demonstrate that the proposed algorithm significantly enhances constellation clarity and compactness. The MSE is reduced by up to 18.77 dB, while ISI suppression reaches a maximum improvement of 14.32 dB, thereby significantly improving the overall performance of the communication system.