In this study, the nano-Fe3O4/saponite composites were prepared by hydrothermal synthesis and coprecipitation method, and used to remove 2,4-dichlorophenol (2,4-DCP) from water. The phase composition, structure, morphology and elemental composition of nano-Fe3O4/saponite composites were characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray fluorescence (XRF). The removal efficiency of 2,4-DCP by nano-Fe3O4/saponite composites under solution with different 2,4-DCP concentration, reaction time and pH were investigated. The results show that the in-situ growth of nano-Fe3O4 on the surface of saponite is more evenly dispersed, which effectively reduces the agglomeration of Fe3O4. The maximum removal of 2,4-DCP by nano-Fe3O4/saponite composites is 178.46 mg/g when the pH value is 6, and the removal of 2,4-DCP reaches saturation when the reaction time is 5 min. The removal kinetics of 2,4-DCP by nano-Fe3O4/saponite composites accords with the pseudo-second-order kinetic model. On this basis, liquid chromatography-mass spectrometry (LC-MS) analysis shows that 2,4-DCP is degraded into chlorophenol and other intermediate products. The research results provide a new, environmentally-friendly and efficient environmental functional material for the degradation of organic pollutants in water.