The invention, which belongs to the technical field of 
network intrusion detection, discloses an intrusion detection method and 
intrusion detection system based on sustainable 
ensemble learning. A multi-class regression model is constructed by using a class probability output and a classification confidence product of an individual learner as training data, so that the decision-making process of the 
ensemble learning has high adaptability to the 
attack type to improve the detection accuracy. At the model updating stage, parameters and decision results of historical models are added into the training process of a new model, thereby completing 
incremental learning of the model. According to the invention, on the basis of the 
ensemble learning fusion plan of the multi-regression model, the decision-making weights of the individual learner during the detection processes for different 
attack types are allocated in a fine 
granularity manner; and the parameters and results of the historical models are used for training the new model, so that the stability of the model is improved and the 
sustainability of the learning process is ensured. Besides, the experiment result is compared with theexisting MV and WMV plans, the accuracy, stability and 
sustainability of the intrusion detection method and 
intrusion detection system are verified.