In this work, the problem of preview saturated control (PSC) for constrained discrete-time delayed systems (CD-TDS) was investigated. First, using an input–output method, a discrete-time system with time-varying delays was formally eliminated, and a discrete-time system with constant time delay was obtained. Then, an augmented error system (AES) was constructed through an auxiliary signal related to state variables, which changed the problem of PSC transform into a problem of robust stability for the interconnected subsystem. Afterward, using the Lyapunov function and linear matrix inequality (LMI) technique, sufficient conditions for the robust stability of the closed-loop system and the design of the PSC laws were given. Finally, numerical simulations were performed, and they demonstrated the validity of the results presented in this paper.