The force increase ratio of the filter core folding machine mechanism can be very large in theory, but due to the elasticity of the components, the actual force increase ratio cannot be adjusted arbitrarily. During the design, in order to increase the actual force increase ratio, the rigidity of the pressure bar, the pressure plate and other members is increased as much as possible, and the contact length between the clamped profile and the clamp is increased to reduce the deformation of the profile. However, as the force increase ratio becomes larger, it is more affected by the elastic deformation of the pressure bar and the dimensional accuracy of the profile. If the profile size is slightly increased, the increase in force ratio is significantly reduced. The size of the clamped profile is slightly reduced or the mechanism is loose, which will cause the clamp to fail. Therefore, the clamping mechanism of the pultrusion machine must be improved to upgrade the clamping reliability.