1. An abnormal behavior detection system using an automatic classification of multiple features, comprising: a feature extraction unit, used to extract features for one or more objects from monitoring data, and establishing feature sets of objects; a behavior model establishing unit, receiving the feature set from the feature extraction unit; then establishing and updating a behavioral model after a cluster analysis; a behavior determining unit, receiving the feature set established by the feature extraction unit and the behavior model from the behavior model establishing unit, and further determining if there is an abnormal behavior; and an output unit, used to output data of the behavior model and determination result of the object's behavior.