After analyzing the characteristics of Immunity Intrusion Detection System, by utilizing prominent characteristics of genetic algorithm and vaccine mechanism, a new hybird immunity intrusion detection model based on genetic algorithm and vaccine mechanism was established. The modeling process is described in detail, such as feature extraction of vaccine, genetic operates to memory detectors and the improvement for detection method. Via application vaccine mechanism into intrusion detection system, the new model has the function of misuse detection and anomaly detection simultaneously. In order to improve the detection matching efficiency, we also present a novel matching algorithm RBNDM. Finally, we evaluated our model using the KDD Cup 1999 Data set. The experiments show that this model can increase the true positive rate of the IDS.