Aimming at the characterristics of fire explosion accidents occurred in the storage tank district of petrochemical enterprises, and following the principles of scientific nature and practicability, the authors adopted fuzzy comprehensive evaluation technique to analyze all factors which have influenced the fire safety of storage tank district in petrochemical enterprises from fire safe management, fire-fighting equipment and fire explosion hazardous area. Futhermore, it has defined the evaluation index of fire safety of storage tank district in petrochemical enterprises,and built up a fuzzy mathematic evaluation model. Finally, the authors put this evaluation technique into practice.