This invention relates to a composite clarification agent used in sugar production. The composite clarification agent is composed of: polymerized AlCl3, organic polymeric materials (including chitosan, chitosan quaternary ammonium salt and dimethyl diallyl ammonium chloride), and ultra-fine powder (including perlitic powder, diatomite and clay) at a ratio of (45-90) :( 1-10) :( 5-50). The composite clarification agent has high electrical neutralization and bridge linkage performances, and has such advantages as low cost, rapid solid-liquid separation and no toxicity. The composite clarification agent is suitable for clarifying mixed juice, filtrate and syrupy in sugar production. The method has such advantages as abundant raw materials, simple process and easy operation.