The present invention discloses a tetra-substituted imidazole synthesis method, wherein amidine and chalcone derivatives are adopted as raw materials and chlorobenzene is adopted as a solvent. Meanwhile, ferric trichloride and iodine are adopted as catalysts. In this way, the tetra-substituted imidazole is synthesized through the oxidative cyclization reaction. The above raw materials of the method are readily available, and the operation of the method is simple. Meanwhile, the method is mild in reaction condition, high in yield and strong in practicality, thus being suitable for industrial production.