To address the problem of degraded tracking performance of traditional preview control in interconnected continuous-time systems under external disturbances, a decentralized robust preview control (PC) method based on equivalent input disturbance (EID) compensation is proposed. First, an EID estimator is designed to achieve online estimation and compensation of external disturbances acting on each subsystem, thereby effectively reducing their influence on system performance. Then, a new equality constraint based on preview information is introduced to construct a decentralized preview controller, and an augmented error system is formulated to transform the controller design problem into the stabilization problem of the error system. Finally, by combining Lyapunov stability theory, linear matrix inequality tools, and singular value decomposition techniques, sufficient conditions are derived to guarantee that the closed-loop system is asymptotically stable and satisfies the H∞ performance indices, and the controller and observer gains are obtained. Numerical simulations on a coupled inverted pendulum platform show that the proposed control strategy reduces the maximum tracking error caused by disturbances from 0.315 7 to 0.048 3, shortens the recovery time to steady state from 213 ms to 25 ms, and decreases the overshoot from 19.58% to 2.06%. These results demonstrate that the proposed method is significantly superior to traditional preview control and sliding mode control, verifying its effectiveness and advantages in disturbance rejection and tracking performance.