Fibrous brucite has very unique structure and physical properties. Brucite fibers were exfoliated into single nanofibers by using dioctyl sodium sulfosuccinate (AOT) as a dispersant through mechanical agitation and ultrasonic dispersion; and then, the nanofibers were modified by stearic acid and (3-aminopropyl)triethoxysilane (γ-APS) compound modification agent. The nanofibers were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis. It is found that AOT has good effect on the dispersion. The single fiber has a consistent morphology, and fibrous brucite is dispersed and modified without destroying the crystal structure. Infrared and thermal analysis shows that the surface modification of fibrous brucite is achieved by forming chemical bonds between the coupling agent and magnesium hydroxide.