Thispaperdealswithanimportantsubjectofrejectingtheabnormaldataintelligentlyinthedynamicdatasystem.Basedontheprincipleofnearestneighboroffuz-zymathematics,anapproachofmathematicallyabstractingthehumanthinkingandphys-icalpracticeknowledgeisdiscussed,anewmethodofautomaticrejectionofabnormalda-taisthenproposed.Theexperimentalresultsshowthatthemethodisavailabletothepractice.