The internal network of the organization is not only faced with the threat of external attackers， but also faced with the insider threat including destruction of the organization network structure， internal information theft and various means of fraud. Because of the characteristics of concealment， destructiveness and diversification of attack methods， the insider threat poses a serious threat to the internal network. Therefore， it is very necessary to study the detection methods of insider threat. This paper analyzes the characteristics of insider threat and expounds the significance of studying the detection methods of insider threat. The existing insider threat detection methods are divided into three categories， namely， detection methods based on abnormal behavior， detection methods based on abnormal audit diary， and other detection methods. The current research status of each aspect is introduced respectively， and the progress of the research status of each aspect is summarized and analyzed.At last， the future research direction of insider threat detection methods is prospected.