With the rapid development of mobile Internet and Internet of Things applications, the traditional cloud computing model can provide centralized remote services, but when the amount of data increases sharply, it has been unable to effectively process the data generated by edge devices. To address these challenges and efficiently utilize distributed computing resources, edge computing emerges. With the rise of edge computing, more and more attention has been paid to its security threats and countermeasures. This paper first introduces the basic definition, architectural features, and current security threats of edge computing, then discusses the privacy protection issues in edge computing, and systematically expounds the latest research results at home and abroad. The application of privacy-preserving computing technology in computing, discusses the development trend of edge computing, and proposes further research directions.