Abstract: Based on analyzing the fouling mechanism of slurry oil in petroleum processing, several antifoulants were prepared including components for cleaning and dispersion, antioxidation, metal passivation and corrosion inhibition. The main cleaning and dispersion component was synthesized in lab using polybutadiene thiophosphoric acid and hexanediol as raw materials. The antifouling performance of the prepared antifoulants was tested. Results showed that using FCC slurry as feed under the testing conditions, with an optimum antifoulant dosage of 150 ?g/g, the antifouling rate of the optimum antifoulant reached 92.07％.