Abstract: This is an article in the field of mineral materials. The tourmaline powder was modified with silane coupling agent KH-171, and the process conditions were optimized with the parameters of contact angle and turbidity of the modified product in liquid paraffin. The test results showed that the contact angle of the resulting modified tourmaline reached 133 ℃ when reacted at 60 ℃ for 2 h at a system pH value of 9, a dosage of modifier KH-171 of 2 mL, and an alcohol-to-water ratio of 1∶5, showing excellent hydrophobic properties. The modified tourmaline was characterized by IR, SEM and XRD. The results showed that the organic functional groups with carbon-carbon double bonds were successfully connected to the surface of tourmaline without changing the original crystal structure, but the agglomeration of tourmaline reduced effectively and showed better dispersion performance.