Abstract: The environmental problems of mines caused by acidic mine drainage from pyrite oxidation have been a challenge in the field of environmental management, controlling pyrite oxidation is the primary way to treat acid mine drainage at its source. The composite material prepared by mechanochemical method with cheap clay minerals and carbonate as raw materials realized efficient passivating inhibition of pyrite oxidation. The results showed that the passivation material prepared by ball milling with the molar ratio of kaolinite to calcium carbonate at 1∶2 and rotating speed at 600 r/min for 1 h significantly inhibited the oxidation of pyrite. After 14 days, the pH value was stable above 7 and the \textSO_4^2 - concentration was only 600 mg/L. The crystal structure of kaolinite was destroyed and disordered by mechanochemical process, and the carbonate was combined with kaolinite to form amorphous substance. The active components such as silicon and aluminum released from the passivation material combined with the iron hydroxide layer on the pyrite surface to form a stable passivation layer, which can prevent the pyrite from contacting with oxygen and water, thus inhibiting the chemical oxidation of pyrite. The preparation process is simple and environmentally friendly, the raw materials are cheap and easy to obtain, and the passivation materials have no risk of environmental pollution. providing a new idea for the source treatment of acid mine drainage.