This study aimed to investigate the effects of laminarin (LA) and ferulic acid (FA) on the gelatinization, rheological properties, freeze-thaw stability, and digestibility of cassava starch (CS). The results indicated that LA increased the peak viscosity, trough viscosity, final viscosity, storage modulus, and loss modulus of CS, while decreasing the breakdown viscosity. Conversely, FA exerted opposite effects. The addition of LA and FA delayed the setback viscosity of CS, thereby retarding short-term aging. In the ternary system, LA mitigated the adverse effects caused by FA, and further enhanced the gel properties, including viscoelasticity, thermal stability, and resistance to short-term retrogradation. Additionally, the short-term freeze-thaw stability of CS gels was enhanced by the inclusion of LA and FA. Fourier transform infrared spectroscopy (FTIR) showed that LA reduced the structural stability of CS, while FA was beneficial for the structural orderliness. However, the degree of orderliness in the starch gel network structure within the ternary system was compromised. Moreover, LA and FA also affected the digestibility of CS, with the CS + LA + FA ternary system exhibiting significantly higher contents of resistant starch and slowly digestible starch compared to CS, which was conducive to stabilizing blood sugar fluctuations. These findings contributed to the practical application of LA, FA, and CS, and provided a data reference for understanding the application of modified bioactive substances in starch-based food processing.