Attapulgite (ATP) clay was modified with different silane coupling agents [3-triethoxysilylpropylamine (KH550), γ-glycidoxypropyltrimethoxysilane (KH560) and γ-methacryloxypropyltrimethoxysilane (KH570)] and used as a decolourizer for bleaching of refined palm oil. The effects of different silane coupling agents on the structure, surface charges and pore structure of ATP were investigated by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, Zeta potential and nitrogen adsorption-desorption isotherm techniques, and the decolourization efficiency of the modified ATP was evaluated by UV-Vis absorbance and Lovibond colour. The results show that the KH550-modified ATP exhibits the best decolourization performance, which can decrease the red-yellow value of refined palm oil by 31.96% and the phosphorus content by 77.69% after bleaching; while the unmodified ATP can only decrease these values by 17.30% and 62.31%, respectively.