Human Flesh search has experienced ten years since Chen Ziyao Event in 2001 to Diary Event in 2010,during this period,human flesh search experienced role transformation from single commenting platform to revealing the truth and condemning immoral things.Human flesh search has been debated on its positive effect and negative effect since its emergence.From the angle of positive effect,this paper analyzes the whole process of the search and tries to clarify network operation mechanism on public opinions.