<p>Silicone rubber (SR), as a unique functional material, has attracted widespread attention and has been applied in various fields, such as soft robotics. Fillers are commonly added to SR to provide it with new functions or enhance its mechanical properties. However, fewer studies have utilized natural fibers as reinforcing materials. Herein, a soft actuator made of modified bamboo fiber (BF)-reinforced SR is designed. The microstructure of modified BF and its impact on SR are analyzed using scanning electron microscopy and Fourier-transform infrared spectroscopy, then the mechanical properties of BF/SR are examined. Additionally, the deformation of the actuator is simulated and experimentally tested. The results show that the BF modified by sodium hydroxide and KH-570 are well dispersed, and exhibit improved interfacial bonding with the SR matrix, leading to enhanced modulus and hardness. Meanwhile, the Ogden 2nd order provides the best fit, and the simulation results and experimental data of soft actuators show good agreement. Soft actuators from modified BF-reinforced SR are significantly enhanced compared to that from pure SR without affecting the ductility required for its normal operation. It not only shows the promising applications of BF/SR polymers, but also indicates the accuracy of the finite element methods for composites and actuators. On the other hand, it also provides a reference for applications of larger sizes of functional fillers in soft actuators.</p>