The invention provides a novel system and a novel method for filtering electric power business data, which are used for solving the sensitive data filtering problem of an electric power business data protection system. The system mainly comprises the parts of a data preprocessor, a data attribute reduction controller, a data filtering controller. A rough set method is adopted to reduce electric power business sets and data complexity, a gene expression method is utilized to build an electric power business data classification model, the sensitive degree of the electric power business data is actively identified on the basis of the classification model, and leakage is prevented through the cooperation of a strategic knowledge base.