The invention discloses an abnormal computer user behavior detection method comprising the steps of 1, preprocessing original data to remove repeated information and error information, and generate formative user identity information, object information, time information and behavior information; 2, performing normal user behavior modeling based on the user identity information, the object information, the time information and the behavior information to build a user behavior base line; 3, based on the user behavior base lien, matching user behaviors generated in real time, and detecting the abnormal user behavior; and 4, further adjusting the user behavior base line for the normal user behaviors generated in real time. According to the abnormal computer user behavior detection method provided by the invention, detection on the abnormal computer user behaviors is achieved.