To suppress unnecessary deformation during the soft actuator's bending and improve the soft manipulator's gripping ability, a soft manipulator with limiting layer materials of PDMS and PTFE was proposed. The stiffness of the limiting layer can be changed by adjusting the mass ratio of PDMS and PTFE, which directly affected the bending angle of the soft manipulator. Considering that the deformation of the strain layer was much larger than that of the constraint layer when the soft manipulator worked, Yeoh and Neo-Hookean form of strain energy function were used to describe the mechanical behavior of the strain layer and the constraint layer respectively. Based on the above models and the principle of torque balance, a mathematical model of the bending angle of the soft actuator was established, and then the influence of the material of the limiting layer and actuator structural parameters on its bending performance was investigated. The stress-strain curve of the limiting layer sample made of PDMS and PTEE with different mass ratios was obtained by uniaxial tensile test, and the material parameters of the Yeoh model were fitted, and then finite element simulation analysis was carried out to determine the optimal proportion of the restricted layer material. Finally, the bending angle of the actuators made of different limiting layers was tested, and the deviation between experimental results and theoretical analysis was within 5%, verifying the mathematical model's accuracy. The end force test results showed that the actuator with the PDMS/PTFE ratio of 8∶1 was better than that of pure silicone soft actuator, and the maximum end force can reach 2.45N. Using a soft manipulator for grasping experiments on various items, the maximum grasping mass was 420g.