A facile strategy has been developed for the preparation of novel poly(acrylic acid)-modified tourmaline/silver (PAA-modified Tm/Ag) composites with good adsorption properties and high catalytic activities. Ag nanoparticles are successfully deposited on poly(acrylic acid)-modified tourmaline (PAA-modified Tm) surfaces via in situ reduction and simultaneously protected by poly(vinylpyrrolidone) (PVP). Fourier transform infrared spectroscopy (FTIR) and zeta potential analysis confirm the formation of PAA-modified Tm, and dispersibility measurements illustrate the introduction of PAA can greatly improve the dispersibilities of Tm in water. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results have confirmed the formation of PAA-modified Tm and PAA-modified Tm/Ag composites. Catalytic studies show that the prepared PAA-modified Tm/Ag composites exhibit high catalytic activities and good recyclabilities for the catalytic reduction of methylene blue (MB). Adsorption tests suggest that the prepared PAA-modified Tm/Ag composites exhibit good adsorption properties. Therefore, the prepared PAA-modified Tm/Ag composites have a high potential for use in the catalytic degradation of organic dyes and adsorption removal of heavy metal ions in wastewater treatment applications.