For the threat of disclosure of user information and privacy caused by personalized search,privacy protection technology in personalized search becomes a recent research hotspot.First of all,the personalized search technology is expounded from four aspects including the collection of personal information,the establishment of user profile,search results sorting and system evaluation. And the advantages and disadvantages of different technologies are compared.Then,the privacy protection technology is discussed in detail from two aspects containing prevention of unauthorized data access and security of released data.In addition,the current research achievements and the limitations of privacy protection in personalized search are analyzed.At last,further problems which need to be solved are presented.