The cylindrical roller bearing (CRB), as a key part of the rotating machine, has a significant influence on the reliability, stability, and safety of the mechanical system in operation. Dynamic modelling of CRB based on kinematics and physics is beneficial to make it clear that the intrinsic excitation mechanism of the defect, revealing the mapping mechanism between the evolution mechanism of the internal failure excitation mechanism and the dynamic behaviors of the CRB. It could provide a theoretical foundation for promoting the accuracy and reliability in the condition operation and maintenance of the CRB. Existing models in the dynamic modelling of the CRB rarely consider the coupled excitation mechanism caused by the composite defect located on the inner and outer raceways, respectively. In view of this, a new dynamic model for the coupled excitation mechanism caused by the composite defects of the CRB is proposed in this article. The models for representing the time-varying mechanical parameter evolution mechanism due to the contact between the roller and the inner or outer raceway defect and between the roller and both the inner and outer raceway defects are deduced and formulated. The mapping mechanism between the excitation mechanism of the composite defect and the evolution law of mechanical parameters such as contact displacement and contact force of the CRB is studied. In addition, the variations in the vibration behaviors of the CRB with the different shaft speed scenarios are investigated. Comparisons between simulation and experiment show that the simulated vibration responses of the CRB are in good agreement with the measured results, and the characteristic defect frequencies calculated from the simulated signal are very close to the measured results. As a result, the effectiveness and accuracy of the proposed model is evaluated. These results have the confidence to provide certain theoretical significance and practical application value for the improvement of the accuracy and reliability in the condition monitoring and maintenance of the CRB.