The inhibitory effect of double-base solid propellants is used to control and prevent the burning degree of exposed areas, induced by longer burning time. In recent years, inhibition with cellulose derivatives including cellulose acetate and ethyl cellulose has become popular, but these monolithic systems usually suffer from the drawback of a high erosion rate and demand high thickness and low burning time. A composite inhibitor based on cotton fibers/epoxy resin containing some chlorinated flame retardants (CFR), which were added in inhibitor composition to control its burning process, is described in this article. The thermal properties of the composite inhibitor were studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), thermomechanical analysis (TMA), and flame retardancy. Finally, the inhibited propellant charge, statically fired at ambient temperature, was found to display a smooth and flat pressure-time profile, confirming the successful performance of the composite inhibition system without the application of any barrier coat.